(a) The original evidences of indebtedness, including documents prepared in connection with purchasing procedure, and all original contracts, invoices, statements, receipts, petty cash tickets, bank statements, cancelled checks drawn upon bank accounts, and other original supporting papers shall be retained in the permanent file of the business office of each state agency. These documents shall be kept in a safe place subject to audit and shall not be destroyed until authorization is given for their destruction by the Legislative Auditor.
(b) With the approval of the Legislative Auditor, a state agency may retain evidences, to satisfy record retention policies, of indebtedness and other contracts, invoices, statements, receipts, petty cash tickets, bank statements, cancelled checks drawn upon bank accounts, and other supporting papers by microform or a form of stored images in a computer system or other form of computer technology in lieu of retaining the originals of such documents.