SECRETARY FOR JUSTICE v. LAM TAT MING AND ANOTHER

FACC No. 9 of 1999

IN THE COURT OF FINAL APPEAL OF THE

HONG KONG SPECIAL ADMINISTRATIVE REGION

FINAL APPEAL NO. 9 OF 1999 (CRIMINAL)

(ON APPEAL FROM CACC No. 615 OF 1998)

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J U D G M E N T

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Chief Justice Li:

1. In the criminal courts of Hong Kong, the prosecution in many cases relies as part of its case on confessions by the accused. Where the accused challenges the confession, the court usually holds a voir dire (i.e. a trial within a trial) to determine whether the prosecution has established that the confession was voluntary. Where the court is not so satisfied, the confession is inadmissible. Where the court is so satisfied, the confession is admissible but the court retains a discretion to exclude it. This has been called the residual discretion since it relates to evidence which is admissible.

2. This appeal concerns the proper approach to the exercise of this residual discretion in relation to a voluntary confession. Where a law enforcement agency through an undercover operation obtained from a suspect a confession which is held to be voluntary, how should the court approach the exercise of this residual discretion ? The same considerations would apply to confessions and admissions and I shall simply refer to confessions. The Court is solely concerned with the proper approach under the common law in Hong Kong. Both parties to the appeal have not relied on or drawn attention to any provision in the Basic Law or the Hong Kong Bill of Rights Ordinance, Cap. 383.

THE FACTS

The charges

3. The 1st and 2nd respondents were police officers. They faced charges of corruption offences under section 4(2)(a) of the Prevention of Bribery Ordinance, Cap. 201, of soliciting and accepting between December 1992 and March 1993 protection monies to facilitate triad society members carrying out decoration works at certain flats at a certain housing estate. The 1st respondent faced one charge of solicitation involving $450,000 and three charges of acceptance involving $150,000 on each charge. The charges named a person nicknamed "Ngau Wing" as the person from whom he solicited and accepted these sums. The 2nd respondent faced one charge of acceptance involving $75,000 from the 1st respondent.

The undercover operation

4. It was in October 1994 that the matter first came to the attention of the authorities. At that time, Ngau Wing complained to the Independent Commission Against Corruption "("ICAC") and made the allegations in the four charges against the 1st respondent. After the complaint was made, the ICAC lost contact with him. But in June 1996, he was relocated, brought to the ICAC, videoed under caution and arrested for offering an advantage to a public servant.

5. As was known to the ICAC, Ngau Wing was a bad character. He had criminal convictions going back more than 30 years and had been sentenced to a training centre in 1965. He had become a member of a triad society in 1963, was convicted in the 1970's of being a member and he remained a member. All this was admitted by him at the trial of the respondents.

6. The ICAC then decided to mount an undercover operation using Ngau Wing and Heung Kai, an ICAC officer. Its primary objective was to obtain evidence to support the allegations he had made. Secondary to that was the prospect that further corruption might be uncovered. In return for his co-operation, he and the then Attorney-General entered into agreements under which he was granted immunity from prosecution. This immunity covered, as was admitted by Ngau Wing at the trial, a catalogue of criminal activities between 1963 and October 1994 involving triad society membership, unlawful money lending, operating a gambling establishment, bribing police officers for protection from raids on gambling establishments, possessing false identity cards, selling and exhibiting obscene video-tapes, and the assault and criminal intimidation of debtors and those close to them. But the immunity expressly did not extend to the prospective prosecution of the offence for which he had been arrested.

7. Between November 1996 and April 1997, the undercover operation was mounted. Ngau Wing had telephone conversations and meetings with the 1st respondent and also the 2nd respondent when it emerged that the 2nd respondent was involved. Ngau Wing was accompanied to meetings by Heung Kai. Ngau Wing adopted the role of a senior triad society member and Heung Kai the role of his follower and minder. Throughout the operation, Ngau Wing received instructions from the ICAC. The telephone conversations and the meetings were tape-recorded. For the latter, Ngau Wing and Heung Kai were wired with tape-recorders. There were 39 tapes in all.

The trial

8. During the conversations by telephone and at meetings, the respondents incriminated themselves. The conversations in effect contained confessions. At the trial in the District Court before His Honour Judge Gill, the prosecution sought to rely on the conversations. The respondents challenged their admissibility. A voir dire was held at which the prosecution called Ngau Wing, Heung Kai and an ICAC chief investigator, and relied on the transcripts of the 39 tapes (and their translation).

9. At the end of the voir dire, the trial Judge ruled that the evidence comprising that of Ngau Wing and Heung Kai of conversations with the respondents and the recordings of those conversations was involuntary and thus inadmissible.

10. Following this ruling, the prosecution offered no evidence at the trial proper. Counsel for the prosecution informed the court that, although Ngau Wing was a witness capable and potentially worthy of belief, this was a prosecution which sensibly required some form of supporting or corroborative evidence. The trial Judge dismissed the charges against the respondents and ordered their acquittal at the prosecution's invitation and awarded costs in their favour.

Case Stated and the Court of Appeal

11. The Secretary for Justice appealed by Case Stated under section 84 of the District Court Ordinance, Cap. 336. This posed four questions of law. Before the Court of Appeal, it was common ground between counsel for the Secretary for Justice and counsel for the 1st respondent that the trial Judge had misapplied the test of voluntariness. Although counsel for the 2nd respondent made no concession, the Court of Appeal had no difficulty in so holding. The trial Judge had held that the deception involved in the undercover operation rendered the confessions involuntary. The Court of Appeal rightly held that he had misunderstood the concept of deception in the test of voluntariness and answered the three questions posed accordingly. This aspect is not in issue in this Court.

12. The Court of Appeal's attention was concentrated on the scope of the trial Judge's residual discretion to exclude the confessions which should have been held to be voluntary. This related to the final question posed in the Case Stated, namely, whether upon the facts found "it would have been open to [the trial Judge] to exclude the challenged evidence in the exercise of [his] discretion based in unfairness it having been implicit in [his] decision founded in involuntariness" (which the Court of Appeal held to be wrong) "that [he] found that manifest unfairness had been practised upon the respondents by the undercover operatives ?" The learned Justices of Appeal delivered three separate judgments. They answered this question in the affirmative and dismissed the Secretary for Justice's appeal [1999] 2 HKLRD 735.

13. I should summarise the findings of fact of the trial Judge as set out in his Case Stated:

(a) Heung Kai is an ICAC officer experienced as an undercover agent;

(b) Ngau Wing was under express instructions to seek out the 1st respondent and, when his involvement emerged, the 2nd respondent;

(c) Ngau Wing's purpose and instructions were specific. Maintaining his cover, he had to so engage the respondents that they might make confessions and admissions of the crimes in 1992-3 and to encourage incriminating evidence. He, with Heung Kai, did so;

(d) the subterfuge spanned a number of months with telephone calls and meetings. It was destined to last for as long as was necessary for the objective to be achieved;

(e) the respondents were made to believe over the passage of time that Ngau Wing was looking out for his own interests assisted and protected by Heung Kai;

(f) the respondents came to be unguarded in what they said, treating Ngau Wing and Heung Kai as equals, having swallowed the bait, unmindful of their true identity and the monitoring and recording.

14. But all the facts particularly the transcripts of the 39 tapes are not before us. Without them, it is not possible for the Court to express a satisfactory view as to how the trial Judge should have exercised his residual discretion. The Court is therefore concerned in this appeal with the proper approach to the matter.

Leave to appeal

15. The Appeal Committee certified the following question of law and granted leave to the Secretary for Justice to appeal to this Court:

"What is the scope of the discretion vested in a judge to exclude an admission made to a law enforcement officer by an accused person which is proved to be voluntarily made and where the admission was made in circumstances in which:

(1) the accused was not under arrest or in custody at the time of making the admission; and

(2) the accused was unaware at the time of making the admission that the person to whom it was made was a law enforcement officer and had the maker been aware of the true identity and status of the officer or the agent of the officer he may not have made the admission ?"

Completed offences and suspects

16. At the outset, it is important to observe that by the time the undercover operation started in November 1996, the alleged criminal offences had long been completed and there were suspects. At first the 1st respondent was a suspect and as the operation progressed the 2nd respondent also emerged as a suspect. The purpose of the operation was to obtain confessions from them.

17. This kind of undercover operation should be contrasted with undercover operations by a law enforcement agency conducted where the criminal activities are ongoing and the offences had not been completed. We are not concerned with them in this appeal as different considerations apply to them. There, the purpose is to collect evidence of an ongoing offence and the evidence usually concerns the commission of a crime, although in the course of it, it is possible that evidence of past offences may emerge.

Voluntariness

18. We are concerned with the proper approach to the exercise of the residual discretion in relation to confessions obtained by a law enforcement agency through an undercover operation from suspects whose confessions were voluntary. Although we are not concerned with voluntariness in approaching the residual discretion, it is helpful to bear in mind the rule of voluntariness and the principles relating thereto.

19. The prosecution must establish that the statement made is a voluntary statement in the sense that it has not been obtained from the accused either by fear of prejudice or hope of advantage excited or held out by a person in authority or by oppression. See Ibrahim v. R [1914] AC 599, 609; DPP v. Ping Lin [1976] AC 574 at 597G - 598A, 600D-F, where Lord Hailsham read the word "exercised" in Lord Sumner's classic test in Ibrahim to mean "excited" and also added oppression to that test; R v. Lam Yip-ying [1984] HKLR 419. Oppression in this context is conduct by a person in authority which tends to sap and does sap the will of the accused so that he makes the statement. See R v. Prager [1972] 1 WLR 260, (1972) 56 Cr App R 151; R v. Li Wai-Fat [1977] HKLR 531.

20. Further, a statement signed by the accused as a result of a fraudulent misrepresentation made by a person in authority as to the character of the document is involuntary. See Seeraj Ajodha v. The State [1982] AC 204 at 221F-G where a police officer had falsely informed the accused that he was signing a document of an entirely different character from that which he did sign.

21. In relation to the person in authority, it is important that the accused actually perceives the person in question to be a person in authority. See Deokinanan v. R [1969] 1 AC 20.

22. Although the principles relating to voluntariness were developed in a historical context when the accused had few if any safeguards, they are well settled. Whilst judges should not extend them, they must not whittle them down. See DPP v. Ping Lin [1976] AC 574, 599H - 600C (Lord Hailsham); R v. Chow Chi-hing [1993] 2 HKC 214 at 217E (Litton JA). The rule of voluntariness as established by these principles is an essential safeguard for the accused against the coercive power of the law enforcement agencies.

23. The underlying rationale is based both on the need to ensure the reliability of confessions as well as the right of silence. In this context, judges often refer to the maxim nemo debet prodere se ipsum, no one can be required to be his own betrayer and some judges refer to the right as the right to silence or the privilege against self-incrimination. I shall refer to it as the right of silence. See R v. Lam Chi-ming [1991] 2 HKLR 191 at 197E (Lord Griffiths), R v. Sang [1980] AC 402 at 436 D-F (Lord Diplock), 456 G-H (Lord Scarman). The right of silence is deeply rooted in the common law. It has been analysed to embrace a number of immunities. In relation to a suspect, he has a specific immunity whilst being interviewed by law enforcement officers from being compelled on pain of punishment to answer questions of any kind. See R v. Director of Serious Fraud Office Ex parte Smith [1993] AC 1 at 30E - 31B. He has the right of silence. The suspect's right of silence involves a right to choose whether to speak or to remain silent. In particular, he has a right not to incriminate himself.

The Secretary for Security's rules and directions

24. The suspect's right of silence is protected by the "Rules and Directions for the questioning of suspects and the taking of statements" promulgated in October 1992 by the Secretary for Security for the law enforcement agencies ("the Secretary for Security's rules and directions"). See Special Supplement No 5 of the Hong Kong Government Gazette on 2 October 1992. These replace the Judges' Rules previously adopted by the courts. Under these rules and directions (and previously the Judges' Rules), as soon as a law enforcement officer has evidence which would afford reasonable grounds for suspecting that a person has committed an offence, he shall caution the suspect before putting any or any further questions to him. The terms of the caution are well known:

"You are not obliged to say anything unless you wish to do so but what you say may be put in writing and given in evidence."

The purposes of the caution include reminding the suspect of his right of silence. Hall v. R [1971] 1 WLR 298 at 301G (Lord Diplock).

25. In this case, the 1st respondent was a suspect and the 2nd respondent came into the picture as a suspect. Mr Bruce SC for the Secretary for Justice accepts that in the absence of an undercover operation, a law enforcement officer, before putting any questions, would have to caution them in accordance with the Secretary for Security's rules and directions.

The residual discretion

Fair trial

26. The judge has the overriding duty to ensure a fair trial for the accused according to law. For this purpose, he has what should be regarded as a single discretion to exclude admissible evidence, including a voluntary confession, whenever he considers it necessary to secure a fair trial for the accused. The essential question is not whether the law enforcement agency has acted unfairly in a general sense. It is no part of the court's function to exercise disciplinary powers over the law enforcement agencies or the prosecution as regards the way in which evidence they seek to adduce at trial was obtained by them. See R v. Sang at 436G (Lord Diplock); R v. Cheung Ka-fai [1995] 2 HKCLR 184 at 195 line 40 (Litton VP). The court's function is to consider whether it would be unfair to the accused to use the confession though voluntary against him at his trial.

27. The test of unfairness is not that of a game governed by a sportsman's code of fair play. See R v. Sang at 456D - E; R v. Swaffield (1997-8) 192 CLR 159, 185-6, para. 35 (Brennan CJ). Unfairness in this respect is to be judged against and only against what is required to secure a fair trial for the accused. R v. Sang at 453C (Lord Scarman); R v. Scott [1989] AC 1242, 1256A-B. However, it is important to observe that in a just society, the conviction of the guilty is in the public interest, as is the acquittal of the innocent. See R v. Sang at 437B (Lord Diplock), 456E - F (Lord Scarman); Attorney-General v. Lam Man-wah (No. 2) [1992] 2 HKC 70 at 72C.

28. The requirement of a fair trial for the accused involves the observance of principles including the following which are relevant in this appeal: (1) No man is to be compelled to incriminate himself; his right of silence should be safeguarded. (2) No one can be convicted except upon the probative effect of admissible evidence. To ensure a fair trial for the accused, the court will exclude admissible evidence the reception of which will compromise these principles. R v. Sang at 436H - 437D (Lord Diplock) and 455C - E (Lord Scarman).

29. Thus, where a confession has been obtained in breach of the Secretary for Security's rules and directions (and previously the Judges' Rules), this is a matter to be considered by the court in deciding whether to exercise its discretion to exclude. This should be regarded as relating to the principle in (1). The case of R v. Payne [1963] 1 WLR 637 should also be regarded as relating to the principle in (1). See R v. Sang at 435D (Lord Diplock), at 455D (Lord Scarman). The defendant subjected himself to a medical examination at a police station following a car collision after it was made clear to him that its purpose was to see if he was suffering from any illness and disability and it was no part of the doctor's duty to examine him to determine his fitness to drive. The judge in his discretion excluded the doctor's evidence that he was unfit to drive.

30. The following should be regarded as relating to the principle in (2). The judge may in his discretion exclude admissible evidence where its prejudicial effect is out of proportion to its probative value. And he may in his discretion exclude admissible evidence where it is so unreliable that no jury (or a judge when sitting alone as a judge of fact) properly directed may convict.

Undercover operations

31. In this appeal, we are concerned with a voluntary confession made by a suspect to an undercover agent and an undercover officer of a law enforcement agency.

32. Where there is no undercover operation, and a suspect is questioned by a law enforcement officer, the suspect should first be cautioned under the Secretary for Security's rules and directions. The caution would remind him of his right of silence. He is reminded that he has a choice whether to speak or to remain silent. If he chooses to speak and confesses, the confession to be admissible must be established to be voluntary. Thus, the suspect has the safeguard of the caution as well as the safeguard of the rule of voluntariness. In this situation, where a caution has been administered and the confession is established to be voluntary, it has been rightly observed in many Hong Kong authorities that the residual discretion to exclude the admissible evidence consisting of the voluntary confession should seldom be employed. First, because relevant and admissible evidence would be withdrawn. Secondly, because the kind of conduct complained of should already have excluded the confession as involuntary. See R v. Lam Yip-ying [1984] HKLR 419 at 424G; R v. Chow Chi-hing [1993] 2 HKC 214 at 217E (where Litton JA described the discretion as very limited); R v. Chan King-hei [1995] 1 HKCLR 288 at 292 line 40 (Mortimer JA said the circumstances for its exercise will be rare). However, circumstances may still arise for its exercise; for example, where its prejudicial effect is out of proportion to its probative value.

33. That situation must be contrasted with the situation where an undercover operation is mounted. It would be absurd to suggest in the context of such an operation that a caution could be administered to the suspect. He would of course not know that he is facing a law enforcement officer. (For present purposes, whether he is an officer or an outside agent of the law enforcement agency makes no difference and I shall simply refer to both as undercover officers or undercover agents interchangeably). And the rule as to voluntariness for which it is important that the person in authority is perceived as such by the suspect would have no application. The suspect therefore would not have the benefit of the safeguards of the caution and the voluntariness rule.

34. In the context of a confession of criminal conduct, the identity of the person to whom it is made may be a crucial factor in deciding whether to speak. It is one thing to make a confession to a friend or a trusted associate. It is quite another thing to make it to a person in authority. A suspect who makes a confession to an undercover officer might well have refused to make the confession to the officer had the accused known the officer's true identity.

35. The law recognises that the use of undercover operations is an essential weapon in the armoury of the law enforcement agencies; particularly their use when the criminal activities are ongoing but also their use after crimes are completed to obtain evidence to bring the criminal to book. The use of undercover operations plays an important part in society's struggle to combat crime especially serious crime, whether it be corruption, trafficking in dangerous drugs or terrorism. But the success and indeed viability of such undercover operations depend upon the concealment of the true identity of the law enforcement officer in order to establish the appropriate relationship with the alleged wrongdoers. They therefore unavoidably involve elements of subterfuge, deceit and trickery. The law accepts that law enforcement agencies may find it necessary to resort to tactics of that kind.

36. Where those tactics result in a confession that is voluntary and therefore admissible, the court will have to consider whether to exclude it in its discretion in discharge of its duty to ensure a fair trial for the accused. Thus, the court may exclude the confession where the confession or evidence of it is so unreliable that no jury properly directed may convict; for example, where the recording is so poor or in the absence of a recording, the recollection of the undercover agent is so poor that it should not be allowed to go before a jury.

37. And the court may exclude it where the right of silence of the accused has been infringed. In the context of an undercover operation involving a suspect, when could it be said that his right of silence is infringed ? In answering this question, the law has to apply practical commonsense.

38. Where the undercover officer plays a passive role and hears or overhears the confession or records it, there can be no basis for rejecting it. Keeton (1970) 54 Cr App R 267 and HKSAR v. Ng Wai-man [1998] 3 HKC 103 are examples of this situation. It has been volunteered freely without interrogation on the part of the officer even though he has misrepresented his identity thereby inducing the suspect to believe that he is speaking to a person who is not a person in authority.

39. The real problem arises where the undercover officer plays an active role in procuring the confession from the suspect by asking questions. If it were not an undercover operation, the suspect would have to be cautioned reminding him of his right of silence and enabling him to make a choice whether or not to speak. With an undercover operation, this obviously could not be done. In this situation, once the officer actively questions the suspect, we enter into an area which may engage the exercise of the residual discretion.

40. How it should be exercised will depend on what follows. If all the officer does is to draw attention to the incident which gives rise to the offence charged, in the absence of any other relevant circumstances, there is no persuasive reason for excluding a confession made. The officer is doing no more than providing an opportunity for the suspect to speak. If however what the officer does amounts to interrogation, the discretion would ordinarily be exercised so as to exclude the confession. Such an interrogation would constitute a derogation of the accused's right of silence and thus prejudice his fair trial. Whether the conversation amounts to an interrogation would have to be determined having regard to all the circumstances. As a matter of fact, whether such an interrogation can feasibly be conducted in the context of an undercover operation without blowing the cover, would depend on the relationship between the suspect and the undercover officer in his posed capacity.

41. In the exercise of the residual discretion whether to exclude a voluntary confession, the courts may take into account as a factor the gravity of the offence. However, it would not be right to give great weight to this consideration because to do so would be to devalue the right to a fair trial to which all persons are entitled for all offences. But it is a relevant factor. The law's approach to this matter has to take into account community interests, as well as the rights of suspects.

42. It is necessary to emphasise that the residual discretion is a judicial discretion which is to be exercised in a principled way. But the occasions where its exercise may have to be considered will involve a wide variety of facts and circumstances. Ultimately, the courts will have to apply the proper approach in a commonsense way.

43. We are concerned with a confession obtained through an undercover operation where the crimes had already been committed and there is a suspect. In this situation, the exercise of the residual discretion is likely to be engaged on the approach laid down in this judgment. That situation is to be contrasted with the undertaking of undercover operations to uncover ongoing criminal activities. There, "the accusatory stage" with a suspect will, generally speaking, not have been reached and different considerations would apply even where incriminating admissions are made of past offences.

Hong Kong authorities

44. There are a number of authorities in Hong Kong on the residual discretion. It is unnecessary to refer to them in detail. They are broadly consistent with this judgment and in any event should now be read subject to and consistent with this judgment. However, three matters arising from these authorities should be referred to.

45. First, in the often cited judgment of Roberts CJ in R v. Lam Yip-ying [1984] HKLR 419, the residual discretion was formulated in this way (at 424G). The Judge should ask himself:

"If the judge is so satisfied [i.e. that the statement was voluntary] and the evidence suggests that it was obtained "unfairly" or that its use in evidence would be unfair, should he exercise his discretion to exclude it ?"

The first limb of the test of evidence having been obtained unfairly is inappropriate and should be discarded. The test should only be that in the second limb, whether its use in evidence against the accused at his trial would be unfair. And unfairness is to be judged against what is required to secure a fair trial for him.

46. Further, in summarising the principles relating to voluntariness, Roberts CJ used the simpler word "deception" in substitution for fraudulent misrepresentation. This is unsatisfactory and may well have led the trial Judge in this case astray. As stated above, fraudulent misrepresentation in this context relates to the character of the document.

47. Secondly, in R v. Cheung Hon-yeung [1993] 1 HKCLR 292 at 300 line 30 - 301 line 10, Power JA in discussing the residual discretion treated the exclusion of statements not ruled to be voluntary as subject to the residual discretion. Power VP repeated this passage in R v. Lam Ka-fai [1995] 1 HKCLR 155 at 161. It is not right to treat involuntary statements as subject to the residual discretion. They are legally inadmissible evidence and must be excluded; the court has no discretion in such a case. Power VP in these judgments referred to categories of the residual discretion. As stated in this judgment, the better approach is to regard the residual discretion as a single discretion.

48. Thirdly, in Lee Yi-choi [1985] 1 HKC 578, the applicant was convicted of murder. He was in custody having been charged. Evidence of a confession had been given by a police officer who after the applicant had been charged was introduced into the applicant's cell under the guise of a fellow prisoner. The officer was instructed not to coax the prisoner to say anything but to listen to him and let him speak freely. The conversation was initiated by the applicant. It took about an hour after which they slept in the cell and the officer was released from the cell the following morning and he then make a note of the conversation (see 584G - 585A). The Court of Appeal held that the confession was unfairly procured by a person, who was in fact a person in authority, as a result of a trick and the trial Judge should have excluded it in the exercise of his discretion. Mr Bruce SC appearing for the Secretary for Justice invited us to consider the correctness of this decision. The applicant was more than a suspect. He had been charged and was in custody. The Secretary for Security's rules and directions provide that it is only in exceptional cases that questions relating to the offence should be put to the accused after he has been charged or informed that he may be prosecuted. It is unnecessary to consider in this appeal the correctness of that decision involving an accused who had been charged and was in custody. In any event, that decision may be distinguishable on the ground that the evidence of the confession was unreliable as the officer could only make a note of the conversation the next morning, although this aspect was not mentioned in the judgment.

The English authorities

49. The Court of Appeal referred to a number of English authorities decided after the enactment of the Police and Criminal Evidence Act 1984 (PACE). Sections 76 and 78 are relevant to confessions.

50. By sec. 76(2), where it is represented that the confession was or may have been obtained (a) by oppression of the person who made it; or (b) in consequence of anything said or done which was likely in the circumstances to render it unreliable, the court shall exclude it except and in so far as the prosecution proves that the confession (notwithstanding that it may be true) was not obtained as aforesaid.

51. Section 78 confers a discretion on the court to exclude evidence (which has been held to include confessions) if it appears to the court having regard to all the circumstances, including those in which the evidence was obtained, the admission would have such an adverse effect on the fairness of the proceedings that the court ought not admit it. The position at common law relating to the court's power to exclude evidence at its discretion is specifically preserved by sec. 82(2). It has been held that the court's discretion under sec. 78 to exclude evidence in the interests of a fair trial is at least as wide as that conferred by the common law and the criteria are the same. See R v. Khan [1997] AC 558, 578E; R v. Christou and Wright [1992] 1 QB 979, 988E - F. The English authorities on the discretion under sec. 78 to exclude in the interests of a fair trial evidence obtained through undercover police operations afford helpful illustrations of where the line may be drawn, which are applicable to the similar common law discretion to be exercised to secure a fair trial for the accused.

52. On the acceptable side of the line are cases concerning ongoing criminal activities where the evidence relates to the commission of the offence. Such cases are: R v. Maclean and Kosten [1993] Crim LR 687; R v. Cadette [1995] Crim LR 229; R v. Smurthwaite and Gill (1994) 98 Cr App R 437 where the judgment referred to a number of factors that may be taken into account (at 440 - 1); and R v. Christou and Wright [1992] 1 QB 979 where during the course of ongoing criminal activities, admissions made in relation to the ongoing offence were obtained from the accused.

53. Further examples on the acceptable side of the line are R v. Bailey (1993) 97 Cr App R 365 where the appellants made damaging admissions in conversation in a bugged police cell, although the police had lulled them into a sense of security by leading them to believe they did not want them to share a cell.

54. In R v. Jelen and Katz (1990) 90 Cr App R 456, the evidence went beyond overhearing of an accused in conversation. It involved the initiation by the police agent of a tape recorded conversation with the accused in which the police agent deceived the accused. But although there was an element of entrapment, it was held there was nothing unfair in the conduct of the conversation. Note however that aspects of this judgment were subsequently criticised in R v. Christou and Wright [1992] 1 QB 979 at 990 B-E.

55. Examples on the unacceptable side of the line include R v. Mason (1988) 86 Cr App R 349 where a confession was obtained from the accused (though not in an undercover operation) consequent on the police falsely telling the accused and his solicitor that it already had incriminating evidence concerning him. And R v. Bryce (1992) 95 Cr App R 320 where questions addressed by the undercover police officer to the accused went to the vital issue of dishonesty in a handling stolen goods charge and was held to be an interrogation with the effect if not the design of using an undercover operation to circumvent the Code of Practice for police questioning. Further, in that case, there was no means of showing by a neutral and reliable record as to what was or was not said.

Australian and Canadian authorities

56. The Court's attention was also drawn to authorities in Australia and Canada. In Australia, a wider common law discretion to exclude has been developed to supplement the exclusion of involuntary confessions which is based on considerations of voluntariness, reliability, unfairness to the accused and public policy which considerations will often overlap. See R v. Swaffield (1997-8) 192 CLR 159.

57. In Canada, the matter has developed based on the right to silence held to be included in section 7 of the Canadian Charter of Rights and Freedoms. That section provides that: "Everyone has the right to life, liberty and security of the person and the right not to be deprived thereof except in accordance with the principles of fundamental justice." See R v. Broyles (1991) 9 CR (4th) 1; R v. Hebert (1990) 77 CR (3d) 145.

Answer to the certified question

58. The certified question of law has been set out earlier in this judgment under the heading "Leave to appeal". Ultimately, it has to be answered by reference to the common law in Hong Kong. In summary, in exercising the residual discretion to exclude a voluntary confession, the judge has to consider whether it would be unfair to the accused to use the confession against him at trial and unfairness is to be judged against what is required to secure a fair trial for him. The protection of his right of silence is a principle of a fair trial. In the context of an undercover operation, whether his right of silence has been jeopardised is relevant.

Answer to the relevant question in the Case Stated

59. The relevant question in the Case Stated has been referred to under the heading "Case Stated and the Court of Appeal". As has been pointed out earlier in this judgment, the Court can only answer this question satisfactorily with all the facts, particularly the transcripts of the 39 tapes, which are not before us. The trial Judge would have to consider all the facts according to the approach as laid down in this judgment in deciding the exercise of his residual discretion.

Orders

60. Accordingly, I would make the following orders:

(1) The appeal is allowed.

(2) The acquittals and the costs order made by the trial Judge in favour of the respondents are reversed.

(3) The matter is remitted to His Honour Judge Gill for the trial to be resumed.

(4) There be no order as to costs before the Court of Appeal and this Court.

Mr Justice Litton PJ:

61. I agree.

Mr Justice Ching PJ:

62. I agree with the judgment of the Chief Justice.

Mr Justice Bokhary PJ:

63. I agree with the judgment of the Chief Justice.

Sir Anthony Mason NPJ:

64. I also agree with the judgment of the Chief Justice.

Chief Justice Li:

65. The Court, being unanimous, makes the following orders:

(1) The appeal is allowed.

(2) The acquittals and the costs order made by the trial Judge in favour of the respondents are reversed.

(3) The matter is remitted to His Honour Judge Gill for the trial to be resumed.

(4) There be no order as to costs before the Court of Appeal and this Court.