London Local Authorities Act 1991

15 Powers of entry

(1) Any duly authorised officer or duly authorised officer of the London Fire and Civil Defence Authority (on production, if so required, of a duly authenticated document showing his authorisation) or any constable, may at all reasonable times enter upon, inspect and examine any premises which are, or which he has reasonable cause to believe are—

(a) used, represented as being used, or intended to be used as an establishment for special treatment without the requisite licence; or

(b) used in contravention of the terms, conditions or restrictions on or subject to which a licence is granted;and may do all things reasonably necessary for the purpose of ascertaining whether an offence has been committed.

(2) Subsections (2), (3) and (4) of section 287 of the [1936 c. 49.] Public Health Act 1936 shall apply in respect of entry to premises for the purposes of this section as they apply to entry to premises for the purposes of subsection (1) of that section.

(3) Any person who intentionally obstructs any person acting in the exercise of his powers under this section shall be guilty of an offence and shall be liable on summary conviction to a fine not exceeding level 3 on the standard scale.