(1)A justice of the peace may exercise the power in subsection (2) in relation to premises in Wales used wholly or mainly as a dwelling if satisfied on sworn information in writing—
(a)that there are reasonable grounds for believing that an offence under section 38(1), (2) or (4) has been committed in the area of a local authority, and
(b)that it is necessary to enter the premises for the purpose of ascertaining whether such an offence has been committed.
(2)The justice may issue a warrant authorising an authorised officer of the local authority to enter the premises, if need be by force.
(3)The warrant continues in force until the end of the period of 28 days beginning with the date on which it was issued.