A correctional officer (however described) or a police officer of a participating State who is authorised under a permit issued under a corresponding interstate law to escort a person imprisoned in that State to or through New South Wales is authorised, while in New South Wales--
(a) to take and keep custody of the person for the purposes and period set out in the permit, and
(b) to take and keep custody of the person for the purpose of returning the person to the participating State.