15.—(1) A warrant issued under regulation 14 must indicate—
(a)the subject matter and purpose of the investigation;
(b)the nature of the offences created by regulations 22 to 24.
(2) The powers conferred by regulation 14 are to be exercised on production of a warrant issued under that regulation.
(3) If there is no one at the premises when the named officer proposes to execute such a warrant he must, before executing it—
(a)take such steps as are reasonable in all the circumstances to inform the occupier of the intended entry; and
(b)if the occupier is informed, afford him or his legal or other representative a reasonable opportunity to be present when the warrant is executed.
(4) If the named officer is unable to inform the occupier of the intended entry he must, when executing the warrant, leave a copy of it in a prominent place on the premises.
(5) In this regulation—
“named officer” means the officer named in the warrant; and
“occupier”, in relation to any premises, means a person whom the named officer reasonably believes is the occupier of those premises.