Employees charging the U.S. government for work they didn't do, swindling taxpayer' money to the tune of $18 million — those are the accusations in a new report by the U.S. Patent and Trademark Office's watchdog. Our Washington bureau reporter Alberto Pimienta explains why the problem could extend beyond that single agency.

Getting paid for not doing the work — that's what happened at the U.S. Patent and Trademark Office.

According to an investigation by the agency's inspector general (IG), employees who review patents falsely claimed to work almost 288,500 hours.

They cheated taxpayers out of $18.3 million over 15 months.

"My usual reaction is that there is an awful lot of time where people aren't working in most places," said Alex Howard, a senior analyst for the Sunlight Foundation. "The difference is that there's not an inspector general to go and ask questions."

The Sunlight Foundation says at least 10 federal agencies right now don't have anyone watching for potential irregularities.

According to the Project on Government Oversight, the CIA, the Department of Defense, the Department of Energy, and the U.S. Postal Service are some of them.

"Every one of the major agencies should have a permanent IG, the president should be nominating them in a timely fashion, and the Senate should be confirming them in a timely fashion," Howard said. "They are an essential part of the accountability that we expect to see in the federal government."

In a statement, the Patent and Trademark Office says the report "serves as a resource in our ongoing efforts to improve."

They say they are "…committed to analyzing the recommendations offered by the OIG, continuing to conduct our own review, and, if needed, improving the extensive measures already implemented."

If employees had actually worked these hours, the report says, the patent backlog in the country would have decreased by almost 16,000 cases.

This is an important number for an agency with a total backlog of almost 550,000 cases, as of July of this year.