99.—(1) A person is required to supply information in the following circumstances—
(a)he is an appropriate person in relation to any dwelling in respect of which—
(i)housing benefit is being paid to an appropriate person pursuant to regulation 76 or 77 (circumstances in which payment is to be or may be made to a landlord); or
(ii)a request has been made by an appropriate person or by the claimant for housing benefit to be so paid; and
(b)the requirer serves upon that appropriate person, whether by post or otherwise, a written notice stating that the requirer—
(i)suspects that there is or may be an impropriety in relation to a claim in respect of any dwelling wherever situated in relation to which he is an appropriate person; or
(ii)is already investigating an allegation of impropriety in relation to that person.
(2) Information required to be supplied under paragraph (1) shall be supplied to the requirer at the address specified in the notice.