Pursuant to authority contained in section 3646 of the Revised Statutes, as amended, and subject to such procedural requirements as may be prescribed by the Treasury Department, there is hereby delegated to heads of departments and agencies whose disbursing officers issue depositary checks, authority to authorize officers or employees of their respective departments or agencies to issue substitutes of such checks, prior to the close of the fiscal year next following the fiscal year in which the checks are issued, and to receive and approve undertakings to indemnify the United States in such cases. The Commissioner of the Bureau of the Fiscal Service, Treasury Department, is hereby delegated authority to issue substitutes of depositary checks drawn by the Director, Operations Group, Treasury Department, or by officers disbursing under delegation from the Director, Operations Group, and to receive and approve undertakings of indemnity in such cases. The authority delegated to the Commissioner of the Bureau of the Fiscal Service may be redelegated by him to such disbursing officers.