No moneys appropriated for the purposes of this chapter shall be available for payments under any contract with the Commission, negotiated without advertising, except contracts with any foreign government or any agency thereof and contracts with foreign producers, unless such contract includes a clause to the effect that the Comptroller General of the United States or any of his duly authorized representatives shall, until the expiration of three years after final payment, have access to and the right to examine any directly pertinent books, documents, papers, and records of the contractor or any of his subcontractors engaged in the performance of, and involving transactions related to such contracts or subcontracts: Provided, however, That no moneys so appropriated shall be available for payment under such contract which includes any provision precluding an audit by the Government Accountability Office of any transaction under such contract: And provided further, That nothing in this section shall preclude the earlier disposal of contractor and subcontractor records in accordance with records disposal schedules agreed upon between the Commission and the Government Accountability Office.