Police and Criminal Evidence Act 1984

14 The further conditions mentioned in paragraph 12(a)(ii) above are—

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

(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 the material contains information which—

(i) is subject to a restriction or obligation such as is mentioned in section 11(2)(b) above ; and

(ii) is likely to be disclosed in breach of it if a warrant is not issued;

(d) that service of notice of an application for an order under paragraph 4 above may seriously prejudice the investigation.