Interpretation and General Clauses Ordinance

(1)
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.
(2)
Any direction by the Chief Executive under subsection (1) may be
given—
(a)
in anticipation of any absence or inability occurring; or
(b)
subsequently thereto and may relate back to the commencement of such
                    absence or inability.
(3)
Where any Ordinance confers powers or imposes duties upon a public officer and
                a new post is subsequently created in the same or another Government department, the
                Chief Executive may, by notice in the Gazette, direct that the said powers and
                duties or any of them shall be exercised by any holder of the new post so created,
                either to the exclusion of or in addition to the first named public officer or
                otherwise.