31(1)A police officer of at least the rank of superintendent may by a written order signed by him give to any constable the authority which may be given by a search warrant under paragraph 28.S
(2)An order shall not be made under this paragraph unless the officer has reasonable grounds for believing—
(a)that the case is one of great emergency, and
(b)that immediate action is necessary.
(3)Where an order is made under this paragraph particulars of the case shall be notified as soon as is reasonably practicable to the Secretary of State.