S.C. Code Ann. § 9-13-110

In case the pension fund, or any part thereof, shall, by order of the board or otherwise, be deposited in any bank or invested as herein stated all interest or money which may be paid or agreed to be paid on account of such sums or deposit shall belong to and constitute a part of the fund. But nothing herein contained shall be construed as authorizing the treasurer to deposit such funds, or any part thereof, unless so authorized by the board.