16.—(1) For the purpose of the discharge of any function under these Regulations, the Justifying Authority may, by notice served on any person, require that person to furnish such information as is specified in the notice, within such period as is so specified.
(2) A notice served pursuant to paragraph (1) may only specify such information as is in the person’s possession or which the person may reasonably be expected to furnish.
(3) A notice served pursuant to paragraph (1) may be withdrawn or varied by the Justifying Authority.
(4) The period specified in the notice pursuant to paragraph (1) shall be not less than 28 days unless in the opinion of the Justifying Authority it is necessary for the provision of the information to be expedited.
(5) A notice served pursuant to paragraph (1) shall invite the person upon whom the notice is served to notify the Justifying Authority within 14 days of any grounds upon which the notice ought to be varied or withdrawn under paragraph (3).