(1) The chief officer of an agency:
(a) may, at any time, by signed writing, revoke a warrant issued to the agency; and
(b) must do so, if he or she is satisfied that the grounds on which the warrant was issued to the agency have ceased to exist.
(2) If another agency or the Organisation is exercising authority under the warrant, then before revoking the warrant, the chief officer must inform the chief officer of the other agency or the Director-General of Security (as the case requires) of the proposed revocation.
(3) After revoking the warrant, the chief officer must:
(a) if subsection (2) applies--immediately inform the chief officer of the other agency or the Director-General of Security (as the case requires) of the revocation; and
(b) in any case--give a copy of the instrument of revocation to the Secretary of the Department as soon as practicable.
(4) The chief officer of an agency may delegate his or her power under paragraph (1)(a) to a certifying officer of the agency.
(5) This section does not apply in relation to a warrant that has ceased to be in force.
(6) For the purposes of the application of subsection (1) to a control order warrant issued on the ground that a control order was in force, that ground is taken to have ceased to exist if, and only if, neither that control order, nor any succeeding control order, is in force.