(1) The Authority may appoint in writing such and so many members of its staff, and such and so many other persons who, in the opinion of the Authority, have the expertise or experience necessary, to be authorised officers for the purposes of this Act.

(2) The Authority may revoke in writing an appointment made by it under subsection (1).

(3) An authorised officer shall be furnished with a warrant of his or her appointment by the Authority and shall, when exercising a power conferred by this Act, produce the warrant or a copy of the warrant, together with a form of personal identification, for inspection if requested to do so by any person affected.

(4) The appointment of a person under subsection (1) shall cease where -

(a) it is revoked under subsection (2),

(b) it is for a fixed period and the period expires,

(c) the person was appointed on the basis that he or she was a member of the staff of the Authority, on that person ceasing to be a member of its staff, or

(d) the person resigns from the appointment.