(1)    An enforcement officer may not by virtue of section 246, 247 or 248 enter any dwelling unless a justice has issued a warrant authorising the officer to enter the dwelling.

(2)    A justice may only issue such a warrant if, on an application by the officer, the justice is satisfied—

(a)    that the officer has reasonable grounds for believing that there is material in the dwelling which for the purposes of carrying out any relevant functions the officer wishes to inspect, examine or seize, and

(b)    that any of the conditions in subsection (3) is satisfied.

(3)    The conditions are—

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

(b)    that it is not practicable to communicate with any person entitled to grant access to that material;

(c)    that entry to the dwelling is unlikely to be granted unless a warrant is produced;

(d)    that the purpose of entry may be frustrated or seriously prejudiced unless an enforcement officer arriving at the dwelling can secure immediate entry to it.

(4)    Schedule 17 contains further provision about warrants issued under this section.

(5)    In this Chapter “justice” means—

(a)    in relation to England and Wales, a justice of the peace;

(b)    in relation to Northern Ireland, a lay magistrate;

(c)    in relation to Scotland, a sheriff, stipendiary magistrate or justice of the peace.