LIU KAIBANG, a minor, by his next friend and mother LIU LIJUAN v. LAI JOSEPH TAK, in his personal capacity and in his capacity as the executor of the estate of LAI DENNIS

HCAP 44/2023

[2026] HKCFI 1262

IN THE HIGH COURT OF THE

HONG KONG SPECIAL ADMINISTRATIVE REGION

COURT OF FIRST INSTANCE

PROBATE ACTION NO 44 OF 2023

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DECISION

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Introduction

1.  On 25 February 2025, I made an order granting leave to the parties to appoint a laboratory in Hong Kong to conduct DNA tests for the purpose of determining whether the plaintiff is the natural biological son of the deceased. 

2.  The order was made after a contested hearing. My reasons for making the order are set out in the decision at [2025] HKCFI 1251.  I shall adopt the defined terms used in that decision below.

3.  Under para 3(1)  of the order, leave was granted to the parties to jointly appoint a single laboratory. 

4.  Under para 3(2)  of the order, the parties were given seven days to agree on the choice of the laboratory, but in the event that no agreement could be reached, the court would make a determination taking into account the curriculum vitae of the proposed laboratories and their respective costs and time estimates. 

5.  Parties could not reach agreement within the deadline, each nominating his own expert.  The defendant has proposed as his expert HK.DNA Diagnostics Laboratory Limited, a Hong Kong-based laboratory. The plaintiff has nominated Cellmark Forensic Services, a laboratory based in the United Kingdom. 

6.  The reason why the plaintiff has reached out to laboratories outside of Hong Kong is this.  According to the plaintiff’s solicitors, they had approached 29 private laboratories in Hong Kong, but none of them were able to agree to do the tests.  According to the laboratories, they were not able to conduct DNA tests on body remains or perform post-mortem DNA paternity tests which require exhumation.  They were not able to do so because the DNA samples on a deceased person who has died for some time and been buried, in this case for more than six years, will likely be deformed or degraded, making DNA testing unreliable and difficult.  Some of the laboratories stated that they are able to conduct post-mortem DNA tests only if the deceased had recently passed away such that his saliva, hair or soft tissues are still available. 

7.  The outcome of the plaintiff’s solicitors’ enquiries was that all of the 29 laboratories declined to conduct the tests. Furthermore, according to the laboratories, for a body who had been buried for more than six years, samples would have to be collected from the skeletal remains, and that expertise and equipment are needed to avoid cross-contamination.

8.  As the order required the party to appoint “a laboratory in Hong Kong”, for the plaintiff to engage Cellmark, a variation of the order is required.  In addition, as no agreement on the choice of laboratory can be reached between the parties, in order to break the deadlock, avoid delay, save time and spare unnecessary legal costs, the plaintiff’s position is that the order should also be varied, such that each of the parties are allowed to appoint their own laboratories. 

9.  It is in these circumstances that the plaintiff took out a summons on 23 April 2025 seeking variation of the order. 

10.  The main variations sought are accordingly: 

(1)  The appointment of the laboratory be changed from a single laboratory to separate laboratories for the parties; and

(2)  A laboratory outside of Hong Kong may be appointed. 

11.  The plaintiff’s summons was adjourned to today for substantive argument.  Last week, a consent summons was filed.  Parties now agree to the above two variations and other consequential directions. 

12.  On 19 January 2026, I raised the following queries on the consent summons: 

“3. Why would HK.DNA Diagnostics be regarded as a suitable laboratory given its admitted lack of experience in taking DNA tests on long deceased bodies?

4. Is there any reason for the defendant to oppose the plaintiff’s nominated expert?

5.  Is there any justification for altering the existing order that a single laboratory should be appointed?” 

13.  Parties have now addressed these issues by written submissions, supplemented by oral submissions made today.  This is my decision on the plaintiff’s summons and the consent summons. 

Basis for varying the order

14.  The starting point of the discussion must be the order made last February.  It was made after a contested hearing.  If a party wishes to seek a variation, he must provide a justification why the order should be disturbed. 

15.  Ms Carol Wong, counsel for the defendant, submits that the order was predicated on the expectation that the parties could agree on a mutually acceptable, single source of expert evidence.  This premise has now failed.  The parties are in fundamental disagreement.  Each has proposed a laboratory.  Each party has advanced reasons why the other party’s proposed expert is unsuitable.  In light of the opposition, Ms Wong submits that the appointment of a single joint expert is no longer practicable or suitable.  To force a joint appointment now would either compel one party to accept an expert that he believes to be inadequate or result in a deadlock that further derails the proceedings.  The procedural mechanism has been exhausted and that justifies a variation of the order made last February. 

16.  I do not agree with this submission.  

17.  It was expressly contemplated in the order that the parties might not be able to agree on the choice of laboratory, and it therefore provided for the mechanism that in that event, the parties should put in submissions, and the court would then make a determination.  That is the mechanism set up in para 3(2)  of the order.  Now that there is disagreement, the task of the court is to follow that mechanism and choose between the two proposed candidates, rather than to appoint two separate candidates. 

18.  It is also not correct for Ms Wong to say that the parties would be forced to accept the expert of the other side at the trial.  It remains open for either party to challenge at the trial the qualification, expertise and experience of the single expert and the contents of the final report, if they have a proper basis to do so. 

19.  I will therefore proceed to consider the two candidates and make a determination, but I will come back to the issue of whether there is other ground justifying the variation of the order later.

Challenges posed by post-mortem DNA tests

20.  The deceased passed away in September 2018 and the body has been buried in Hong Kong for more than seven years.  There is no dispute that by now there will have been decomposition in the body.  What one cannot tell is the extent of the decomposition.  However, due to the long lapse of time, there is plainly a possibility that the decomposition has progressed to such an extent that only the teeth and the bones of the body remain, with no soft tissue remaining.

21.  There can be no dispute that this type of post-mortem DNA test poses specific challenges as the DNA samples recovered from such skeletal remains may not be sufficient or of a good enough quality with the result that any test results conducted based on these samples are not reliable.  For instance, degraded or contaminated DNA may be collected, which would render the result inaccurate. 

22.  It is therefore crucial to appoint forensic scientists who possess the relevant experience and the necessary expertise in post-mortem DNA test, as opposed to those who only have experiences in doing DNA tests on live persons or recently deceased persons. 

HK.DNA vs Cellmark

23.  With the defendant’s consent, the plaintiff’s solicitors reached out to HK.DNA and made enquiry about the latter’s experience in conducting post-mortem DNA tests. 

24.  The questions asked were: 

“1. How long had those deceased persons passed away before samples were taken by Mr.Tong and Mr.Sum;

2. Whether samples of the deceased persons were collected after exhumation; and

3.  Whether the results were conclusive or inconclusive (and if so why).”

25.  The answers given were correspondingly: 

“1. We had previously taken the nails and hairs from the deceased persons within 30 days after they passed away.

2. Those samples of the deceased persons were collected before exhumation.

3.  All the results were conclusive.” 

26.  It is clear from the above that HK.DNA has no prior experience in conducting DNA tests on long deceased bodies.  In my view, that places it at a distinct disadvantage if it is to be appointed to be the laboratory for conducting the paternity test in our case. 

27.  Ms Wong argues that HK.DNA nevertheless has the required expertise in doing other types of DNA tests.  Further, it proposes to adopt an advanced technology called the “SNP analysis” rather than the conventional “STR analysis”, the former being more suitable for handling severely fragmented DNA samples, and the STR analysis is what Cellmark appears to be proposing to use. 

28.  I do not have sufficient information at this stage to determine which technology is more advanced or suitable.  The objective fact, however, remains that HK.DNA has no prior experience in conducting DNA tests on long deceased bodies.  It has never applied the SNP analysis on this kind of bodies.  Any opinion it now gives on the SNP analysis, however advanced it may be, is based on academic literature, but not based on actual experience.  As such, I am not able to give much weight to this opinion for present purposes. 

29.  Expertise is to be built upon, among other things, experiences.  The tests that are required in this action require special expertise.  As a matter of fact, HK.DNA has no prior experience doing these tests.  For that reason, I am not satisfied that it is a suitable candidate in this action. 

30.  By contrast, based on the information provided by the plaintiff, Cellmark would appear to have the relevant experiences and expertise. 

31.  According to its written proposal, Cellmark was established in 1987 by the pharmaceutical company ICI (subsequently AstraZeneca)  as the world’s first commercial DNA fingerprinting laboratory.  It is one of the largest ISO 17025 accredited forensic analysis companies in the UK.  It has about 450 employees.  It is contracted by over 80% of the police forces in England and Wales.  In addition, it holds contracts with the military, government agencies, and the private sector.  Cellmark became part of the Eurofins Scientific Group in August 2024. 

32.  As regards its experiences on post-mortem DNA tests, the company originally developed specialist extraction techniques for bone and teeth samples in 2005.  I quote this passage from the proposal below, in which Cellmark’s track record on conducting DNA tests on historical remains and in war zone and disaster situations is set out:

“Since then, we have undertaken over 1,500 body identification cases and, excluding training and validation samples, Cellmark has undertaken DNA testing on ~ 7,400 human bones and ~ 450 human teeth from historic remains (we are contracted to provide a DNA identification service for fallen British Commonwealth soldiers from the first and second world wars and also to the International Committee of the Red Cross for Forensic identification of individuals who have died in conflicts)  as well as more recently interred remains in police investigations and human remains from Disaster Victim Identification cases including the Ethiopian Airlines flight ET302 crash in 2019 …”

33.  According to the above information, Cellmark plainly has the right credentials and is the right match for the task at hand. At the hearing today, the defendant has not mounted any challenge on Cellmark’s experience and expertise.

34.  In my view, Cellmark is a more suitable candidate than HK.DNA to conduct the DNA tests on the Locus Issue. 

35.  Since Cellmark is based in the UK, that would require a third party to take samples in Hong Kong and transport them to the UK.  Ms Wong submits that given that there will be a chain of transfers and multiple parties are going to be involved, this would increase the risk of contamination of the DNA samples.  By comparison, HK.DNA will be able to collect and analyse the samples within the same team locally, thus reducing such contamination risks. 

36.  I agree that this is a relevant factor that should be taken into account in choosing the right candidate.  However, according to the proposal of Cellmark, it also has experiences in dealing with overseas remains.  The proposal also contains a protocol for the collection of DNA samples in this case to safeguard the integrity of the samples.  It appears to me that the contamination risk is manageable and Cellmark has the experience of managing such risk. 

37.  In any event, as remarked above, at the trial, it is open to the parties to query or challenge or raise the issue of contamination as they see fit.  Therefore, this factor would not detract from my view that Cellmark is the more suitable candidate in this case. 

Variation

38.  I therefore conclude that as between HK.DNA and Cellmark, the latter is the more suitable candidate.  There is no justification for departing from the direction that a single laboratory be appointed, and Cellmark should be appointed as that single laboratory.

39.  Due to the lack of suitable laboratories in Hong Kong, an order needs to be made to vary the previous order and allow Cellmark, an overseas institution, to be appointed, and consequential directions need to be given as a result.  In particular, an agent in Hong Kong needs to be appointed to collect the sample.  Directions ought to be given in this regard for taking the matter forward. 

Orders

40.  The parties have jointly come up with a draft order reflecting the points discussed above during the short adjournment. Based on that draft, I would order that paras 3 to 5 of the order dated 25 February 2025 be varied and replaced by the following with effect from today:

“3. The following directions be given for the conduct of the hearing of the Locus Issue:-

(1)  Leave to the parties to jointly appoint Cellmark Forensic Services, a United Kingdom based forensic laboratory (“Lab”), to conduct the following three tests (“Tests”):

(a)  DNA comparison tests against the bodily samples of the Plaintiff and the Defendant, to determine whether the Defendant is the biological paternal uncle of the Plaintiff;

(b)  DNA comparison tests against the bodily samples of the Plaintiff and the samples exhumed from the Deceased’s remains (the “Remains”), to determine whether the Plaintiff is the biological son of the Deceased; and

(c)  DNA comparison tests against the bodily samples of the Defendant and the samples exhumed from the Remains, to determine whether the Defendant is the biological brother of the Deceased, which will serve as a control test for the tests in paragraph 3(1)(b)  above.

(2)  Parties to provide joint instructions to the Lab.

(3)  Each of the Plaintiff and the Defendant do provide their bodily samples as required for the purpose of the Tests to the Agent(s)  (as referred to paragraph 3(4)  below)  in Hong Kong, and leave be given to the Agent(s)  to obtain DNA samples from the Remains for the purpose of the Tests.

(4)  The Agent(s)  shall have expertise in taking DNA samples from skeletal remains and soft tissues from deceased and living persons. The Agent(s)  appointed shall be responsible for collecting, packaging, and delivering DNA samples from the Remains and/or from the Plaintiff and Defendant in Hong Kong to the Lab.

(5)  If the parties cannot agree on the identity of the Agent(s)  within 21 days from the date hereof, each party do lodge and exchange written submissions within 5 days thereafter limited to 3 pages each (font size 14)  stating: (a)  the name of that parties’ proposed Agent(s); (b)  the proposed Agent(s)’ curriculum vitae; (c)  the proposed costs of the Agent(s); and (d)  brief reasons why no agreement can be reached. The Court will determine the choice of the Agent(s)  on paper (unless the Court directs a hearing).

(6)  No bodily sample shall be taken from the Defendant except with his consent. The Court may draw such inferences (if any)  from any refusal to consent as appear proper in the circumstances.

(7)  The Defendant shall renew or reapply for a permit from the Food and Environmental Hygiene Department to exhume the Remains (“Permit”)  after the date of exhumation is scheduled.

(8)  Both parties and/or their legal representative shall be present when the Remains are exhumed and when the DNA specimens from the Remains, the Plaintiff and the Defendant are being obtained by the Agent(s)  respectively in Hong Kong.

(9)  The evidence of the Lab shall be in the form of a signed written report. The question whether the maker of the report has to testify at the trial of the Locus Issue as a condition for the admission of the report into evidence be reserved.

(10)  Each party do ensure that the signed written report referred to in paragraph 3(9)  above be verified by Statement of Truth and a declaration of compliance with the Code of Conduct (Appendix D of the Rules of High Court)  pursuant to Order 38, rule 37C, the Rules of the High Court;

(11)  The Plaintiff do within 21 days from the joint engagement of the Lab inform the Court of the identify of the maker of the report referred to in paragraph 3(9)  above to attend cross-examination if necessary;

4. The hearing of the Locus Issue be adjourned to a directions hearing which shall take place after the completion of the filing and serving the report referred to in paragraph 3(9)  above, with 1 hour reserved (the “Directions Hearing”).

5.  Parties do lodge the jointly proposed directions at least 3 days before the Directions Hearing.”

(Submissions re costs)

41.  This is my order on costs.  The costs of the summons, including the preparation of the affirmations, and the costs of the consent summons be in the cause of the Locus Issue.  Costs of today’s hearing be borne by the defendant, summarily assessed at $40,000, payable on or before 4 February 2026. 

42.  These are my reasons.

43.  I consider that the first set of costs spent by the parties are on identifying a suitable candidate for the DNA tests.  These costs, therefore, form part of the costs of the Locus Issue and should be made costs in the cause. 

44.  Ultimately, the defendant has lost on the merits by nominating an expert which the court does not consider to be suitable.  It took today’s hearing to resolve that issue.  Therefore, the defendant should bear today’s costs.