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

(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.