25.—(1) This paragraph applies to a person—
(a)to whom the Secretary of State repaid contributions before June 1973, and
(b)who is in pensionable employment or comparable British service.
(2) But paragraph (1) does not apply to a person—
(a)to whom a teacher's pension is payable, or
(b)who is in comparable British service and in respect of whom the Secretary of State has paid a cash equivalent or a transfer value since the end of the person's last period of pensionable employment.
(3) A person to whom paragraph (1) applies may, by giving written notice to the Secretary of State, elect to return the contributions to the Secretary of State with interest.
(4) Where a person makes an election under paragraph (3) the person must pay the amount to the Secretary of State within 10 weeks of receiving written notice of the amount.
(5) Interest is payable at the rate of 3.5% per year compounded with yearly rests from the date on which the contributions were repaid to the date on which the payment of the return of contributions is made.