Okla. Admin. Code § 550:1-7-6
Notwithstanding Section 550:1-7-1(a), should a contribution be made through a mistake of fact that is more than the correct amount of participating municipality or member contributions to be paid to the Oklahoma Police Pension and Retirement System by a participating municipality, the Oklahoma Police Pension and Retirement System may refund the mistaken portion of the contribution to the participating municipality within one year of the date on which the mistaken portion of the contribution was made. The Oklahoma Police Pension and Retirement System shall not pay the participating municipality earnings attributable to the mistaken portion of the contribution but shall reduce the amount returned to the participating municipality pursuant to this subsection by the amount of losses attributable to the mistaken portion of the contribution.
Okla. Admin. Code § 550:1-7-6