26.—(1) In relation to a commission, the following are authorised persons for the purposes of this Part:

(a) any member of the commission;

(b) any person appointed under section 8 and authorised by the commission in writing to exercise the powers given under section 28 to authorised persons.

(2) Persons appointed under section 8 may be authorised by a commission to exercise the powers given by this section in respect of a specified matter or event or generally for the purposes of the investigation.

(3) The commission shall provide each authorised person with a warrant identifying the person and indicating that he or she has authority to exercise the powers given under section 28.

(4) When exercising powers under section 28, an authorised person shall, if requested by anyone affected, produce the warrant for inspection.