Intelligence Services Act 1994

5 Warrants: general

(1) No entry on or interference with property or with wireless telegraphy shall be unlawful if it is authorised by a warrant issued by the Secretary of State under this section.

(2) The Secretary of State may, on an application made by the Security Service, the Intelligence Service or GCHQ, issue a warrant under this section authorising the taking, subject to subsection (3) below, of such action as is specified in the warrant in respect of any property so specified or in respect of wireless telegraphy so specified if the Secretary of State—

(a) thinks it necessary for the action to be taken on the ground that it is likely to be of substantial value in assisting, as the case may be,—

(i) the Security Service in carrying out any of its functions under the [1989 c. 5.] 1989 Act; or

(ii) the Intelligence Service in carrying out any of its functions under section 1 above; or

(iii) GCHQ in carrying out any function which falls within section 3(1)(a) above; and

(b) is satisfied that what the action seeks to achieve cannot reasonably be achieved by other means; and

(c) is satisfied that satisfactory arrangements are in force under section 2(2)(a) of the 1989 Act (duties of the Director-General of the Security Service), section 2(2)(a) above or section 4(2)(a) above with respect to the disclosure of information obtained by virtue of this section and that any information obtained under the warrant will be subject to those arrangements.

(3) A warrant authorising the taking of action in support of the prevention or detection of serious crime may not relate to property in the British Islands.

(4) Subject to subsection (5) below, the Security Service may make an application under subsection (2) above for a warrant to be issued authorising that Service (or a person acting on its behalf) to take such action as is specified in the warrant on behalf of the Intelligence Service or GCHQ and, where such a warrant is issued, the functions of the Security Service shall include the carrying out of the action so specified, whether or not it would otherwise be within its functions.

(5) The Security Service may not make an application for a warrant by virtue of subsection (4) above except where the action proposed to be authorised by the warrant—

(a) is action in respect of which the Intelligence Service or, as the case may be, GCHQ could make such an application; and

(b) is to be taken otherwise than in support of the prevention or detection of serious crime.