His disclosures to the United States government led to a massive fraud investigation against the Swiss bank UBS and other banks that had enabled tax evasion by U.S. taxpayers .
In 2007 , the American banker Bradley Birkenfeld story gets out .
banker 's disclosures to the American   government led to a massive fraud investigation against the Swiss bank UBS and other banks that had enabled tax evasion by American taxpayers .
In 2007 , the American banker Bradley Birkenfeld story gets out .