A constable may at any time enter and inspect any premises in respect of which a licence (other than an off-sale licence) is in force, and may also at any time enter and inspect premises in respect of which an off-sale licence is in force if he has reasonable grounds for believing that an offence has been or is being committed on those premises.

If any person fails to admit a constable who demands entry to such premises in pursuance of this section or obstructs the entry to the premises of such a constable, he shall be guilty of an offence.