Summary: GAO was asked to review a file on the loss of a book of ten Government Transportation Requests (GTR's), which was issued to a former certifying officer of the Department of the Interior, and to furnish a determination of liability. Interior received invoices for eight of the ten missing GTR's and requested legal advice from the General Services Administration (GSA) regarding liability for the charges. Since the GTR's were in proper form and valid on their face, and nothing in the record indicated negligence or bad faith on the part of the carriers, the carriers were entitled to payment for the services rendered. Therefore, the certifying officer properly certified the vouchers for payment and is not responsible or answerable for the payments even though they were made for unauthorized services. Interior had been advised by GSA that GAO could relieve the custodian of liability for the GTR's. However, because Interior decided to refer the question of liability to GSA, a complete investigation was not conducted and no recommendation made by the head of the department. Therefore, GAO would not express an opinion on the custodian's liability.