Prevention of Terrorism (Temporary Provisions) Act 1989

2 (1) A justice of the peace may, on an application made by a constable, issue a warrant under this paragraph if satisfied that a terrorist investigation is being carried out and that there are reasonable grounds for believing—

(a) that there is material on premises specified in the application which is likely to be of substantial value (whether by itself or together with other material) to the investigation;

(b) that the material does not consist of or include items subject to legal privilege, excluded material or special procedure material; and

(c) that any of the conditions in sub-paragraph (2) below are fulfilled.

(2) The conditions referred to in sub-paragraph (1)(c) above are—

(a) that it is not practicable to communicate with any person entitled to grant entry to the premises;

(b) that it is practicable to communicate with a person entitled to grant entry to the premises but it is not practicable to communicate with any person entitled to grant access to the material;

(c) that entry to the premises will not be granted unless a warrant is produced;

(d) that the purpose of a search may be frustrated or seriously prejudiced unless a constable arriving at the premises can secure immediate entry to them.

(3) A warrant under this paragraph shall authorise a constable to enter the premises specified in the warrant and to search the premises and any person found there and to seize and retain anything found there or on any such person, other than items subject to legal privilege, if he has reasonable grounds for believing—

(a) that it is likely to be of substantial value (whether by itself or together with other material) to the investigation; and

(b) that it is necessary to seize it in order to prevent it being concealed, lost, damaged, altered or destroyed.

(4) In Northern Ireland an application for a warrant under this paragraph shall be made by a complaint on oath.