The Secretary of the Interior is authorized to accept the surrender of any lease issued pursuant to any of the provisions of this chapter, or any amendment thereof, where the surrender is filed in the Bureau of Land Management subsequent to the accrual but prior to the payment of the yearly rental due under the lease, upon payment of the accrued rental on a pro rata monthly basis for the portion of the lease year prior to the filing of the surrender. The authority granted to the Secretary of the Interior by this section shall extend only to cases in which he finds that the failure of the lessee to file a timely surrender of the lease prior to the accrual of the rental was not due to a lack of reasonable diligence, but it shall not extend to claims or cases which have been referred to the Department of Justice for purposes of suit.