The government is missing $40,000 in newly printed bills and says it doesn't know where they went.

The Bureau of Engraving and Printing discovered last Friday that the money was missing, a Treasury Department spokeswoman said Tuesday.The cash was being shipped from the bureau to the Federal Reserve bank in Minneapolis, she said.

"This determination was made before the shipment left the Washington, D.C., area," she said. "This loss is under active investigation by the U.S. Secret Service and the Bureau of Engraving."

The Treasury Department refused to provide any further details. The Secret Service and the Bureau of Engraving and Printing declined comment.

If it is a case of theft, it would not be the first time it has happened at the bureau.

Last year, Robert P. Schmitt Jr., a bureau employee, was charged with stealing $1.7 million after officials at banks in Maryland told investigators he had made numerous deposits of crisp $100 bills.