3. Any of the functions conferred on the Secretary of State (including functions conferred on him as the territorial authority in relation to evidence in England and Wales or Northern Ireland) under—
(a)section 13 (request for assistance from overseas authorities);
(b)section 14 (powers to arrange for evidence to be obtained);
(c)section 15 (nominating a court etc. to receive evidence);
(d)section 19 (forwarding seized evidence);
(e)paragraph 6 of Schedule 1 to the Act (forwarding evidence),
may be exercised by the Commissioners instead of the Secretary of State where the circumstances mentioned in articles 4 to 8 below occur; and for the purposes of this Order a reference to the Secretary of State in those sections or that paragraph shall be taken to include the Commissioners.