WASHINGTON -- The Internal Revenue Service has awarded an ex-banker $104 million for providing information about overseas tax cheats -- the largest amount ever awarded by the agency, lawyers for the whistleblower announced Tuesday.

Former Swiss banker Bradley Birkenfeld is credited with exposing widespread tax evasion at Swiss bank UBS AG. Birkenfeld himself served roughly two-and-a-half years in prison for a fraud conspiracy conviction related to the case, which resulted in a $780 million fine against the bank and an unprecedented agreement requiring UBS to turn over thousands of names of suspected American tax dodgers to the IRS.

"The IRS today sent 104 million messages to whistleblowers around the world -- that there is now a safe and secure way to report tax fraud and that the IRS is now paying awards," Birkenfeld's lawyers, Stephen M. Kohn and Dean A. Zerbe, said in a statement.

The IRS, which doesn't usually confirm individual award payments, said Birkenfeld signed a disclosure waiver, allowing the agency to confirm his award. "The IRS believes that the whistleblower statute provides a valuable tool to combat tax non-compliance, and this award reflects our commitment to the law," IRS spokeswoman Michele Eldridge said.

In 2006, Congress strengthened whistleblower rewards to target high-income tax dodgers, guaranteeing rewards for qualified whistleblowers if the company in question owes a least $2 million in unpaid taxes, interest and penalties.