Part 2: Lawful interception of communications Chapter 1: Interception and examination with a warrant Section 39: Cancellation of warrants
This section provides that the Secretary of State, a member of the Scottish Government or a senior official acting on their behalf may cancel a warrant at any time. They must do so if the warrant is no longer necessary on any relevant grounds or the conduct authorised by the warrant is no longer proportionate to what is sought to be achieved.