The Federal Reserve made record profits in 2009 and will return $45 billion to the Treasury, after its efforts to prop up the economy created a windfall for the government, the Washington Post reported.

The $45 billion reflects the highest earnings in the 96-year history of the U.S. central bank, the newspaper reported on its website late on Monday. The figure was obtained by calculations based on public documents, the Post said.

The Fed funds itself from its own operations and returns its profits to the Treasury. The largest previous refund to the Treasury was $34.6 billion in 2007, the Post said.

The report said much of the Fed's higher earnings were sparked by the central bank's aggressive program of buying bonds to push interest rates down and stimulate growth.

By the end of 2009, the Fed owned $1.8 trillion in U.S. government debt and mortgage-related securities, up from $497 billion a year earlier, the newspaper reported. It said interest income on the investments was a major source of Fed profits.

The central bank also made money on its emergency loans and on special programs to prop up lending.

Even though it had reported billions of dollars of decline in the value of loans made to bail out investment bank Bear Stearns and insurer American International Group, the Fed received $4.7 billion in interest payments from those loans in 2009, the Post said.

The report said the Fed was due to release its estimate of 2009 earnings on Tuesday.

(Reporting by Deborah Charles; Editing by Eric Beech)