Interpretation and General Clauses Ordinance

When any Ordinance confers a power or imposes a duty upon a public officer and
                such public officer is unable to exercise the powers or perform the duties of his
                office, owing to absence or inability to act from illness or any other cause, the
                Chief Executive may, by notice in the Gazette, direct that such power shall be had
                and may be exercised and such duty shall be performed by a public officer named by,
                or by a public officer holding the office designated by, the Chief Executive,
                subject to such conditions, exceptions and qualifications as the Chief Executive may
                direct.