31 U.S.C. § 711

The Comptroller General may— (1) prescribe regulations to carry out the duties and powers of the Comptroller General; (2) delegate the duties and powers of the Comptroller General to officers and employees of the Government Accountability Office as the Comptroller General decides is necessary to carry out those duties and powers; (3) regulate the practice of representatives of persons before the Office; and (4) administer oaths to witnesses when auditing and settling accounts.