Two fictional companies set up by the Government Accountability Office were approved by Medicare to provide equipment such as wheelchairs despite the fact that the false providers had no customers, as well as no products in stock, said a GAO report released Wednesday.

A Medicare supplier that screens providers paid a visit to the two bogus companies’ offices in Maryland and Virginia. At first, Medicare denied their applications mainly because the vendors didn’t have inventory. But then, the GAO made fake documents by concluding contracts with fictional wholesale contractors. Subsequently, it supposedly left a contact number. When Medicare’s supplier left a message on the answering machine asking for more information, a GAO investigator left “a vague message in return” pretending to be the provider.

Medicare, a United States health insurance program, admitted to have made an estimated $1 billion in illegal payments of $10 billion it spent on wheelchairs, prosthetic devices, canes and other medical supplies, to a certain extent due to fraud, according to the GAO, the audit, evaluation, and investigative arm of the U.S. Congress.

Investigators didn’t manage to complete billing tests for the Maryland business for the reason that they didn't obtain the necessary passwords.

"Had our operation continued successfully, we could have fraudulently billed Medicare for substantial sums - potentially reaching millions of dollars," the GAO report says.

In July, a report made by the Senate subcommittee disclosed that medical suppliers raised $93 million in fraudulent Medicare claims based on prescriptions from deceased doctors.