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.
4.—(1) The Commissioners may exercise the function under section 13 of arranging for evidence in England and Wales or Northern Ireland to be obtained under section 15 where—
(a)a request for assistance has been made in connection with criminal proceedings or a criminal investigation mentioned in section 14(1)(a), and
(b)those proceedings or that investigation relate wholly or mainly to a relevant offence.
(2) For the purpose of making a decision about a request for assistance the Commissioners must exercise the functions in section 14.
5. The Commissioners may exercise the function under section 13 of directing that a search warrant be applied for under or by virtue of section 16 or 17 where a request for assistance has been made wholly or mainly in connection with a relevant offence.
6. The Commissioners may exercise the function under section 15 of nominating a court to receive any evidence to which a request for assistance relates, where the request for assistance has been made wholly or mainly in connection with a relevant offence.
7. The Commissioners may exercise the function under section 19 of forwarding evidence to the court or authority which made a request for assistance where that evidence has been sent to them by a customs officer under section 17 for such forwarding.
8. The Commissioners may exercise the function under paragraph 6 of Schedule 1 to the Act of forwarding evidence to the court or authority which made a request for assistance where the evidence has been received by the court nominated by the Commissioners under section 15.