12.—(1) The registration officer may, at such times as he thinks fit, make inquiries of a person who is shown in the record kept under regulation 8(5) by virtue of an application under that regulation on the grounds set out in sub-paragraph (b) or (c) of regulation 8(4).
(2) In the case of a person who is shown in the record kept under regulation 8(5) by virtue of an application under that regulation on the grounds set out in regulation 8(4)(c), the registration officer shall make the inquiries referred to in sub-paragraph (1) above not later than three years after the granting of the application or the last such inquiries, as the case may be.
(3) The registration officer may treat the failure by a person of whom inquiries have been made to respond to such inquiries within one month of the date on which they were made as sufficient evidence of a material change in circumstances.