The Federal Reserve is blocking a congressional investigation into bailout decisions made under Treasury Secretary Timothy Geithner's leadership.

The Fed is telling a bailout watchdog not to share documents requested as part of a House investigation into the bailout of failed insurance conglomerate American International Group Inc.

A letter from the special inspector general for the financial bailout to California Rep. Darrell Issa says, the Fed "has directed us not to provide you with the documents it has provided to us."

Issa is the top Republican on a committee investigating the New York Fed's suppressing details about deals that sent billions of AIG bailout dollars to other big banks.

Geithner was president of the New York Fed when the decisions were made.