(a) As used in this Code section, "past service as an assistant district attorney" shall include service rendered in that position pursuant to an Act authorizing assistant district attorneys in certain judicial circuits, Ga. L. 1970, p. 716, as amended, notwithstanding its subsequent repeal.

(b) Any member who is subject to Code Section 47-2-262 may receive creditable service under this chapter for past service as an assistant district attorney or as an employee of the Prosecuting Attorneys' Council of the State of Georgia upon payment to the board of trustees of the employee contributions which he would have paid had he been a member of the retirement system at the time such past service was rendered. The basis for employee contributions to obtain creditable service under this Code section shall be the state salary paid to the members claiming such past service at the time the service was rendered.