31 U.S.C. § 712: Investigating the use of public money

The Comptroller General shall—(1) investigate all matters related to the receipt, disbursement, and use of public money; (2) estimate the cost to the United States Government of complying with each restriction on expenditures of a specific appropriation in a general appropriation law and report each estimate to Congress with recommendations the Comptroller General considers desirable; (3) analyze expenditures of each executive agency the Comptroller General believes will help Congress decide whether public money has been used and expended economically and efficiently; (4) make an investigation and report ordered by either House of Congress or a committee of Congress having jurisdiction over revenue, appropriations, or expenditures; and (5) give a committee of Congress having jurisdiction over revenue, appropriations, or expenditures the help and information the committee requests.