Credit Suisse Group AG helped American customers hide as much as $10 billion in assets from the Internal Revenue Service, more than double the amount previously known, according to a U.S. Senate committee, Bloomberg News reported yesterday. A report by the Senate Permanent Subcommittee on Investigations criticized the Zurich-based bank for failing to discipline any senior executives in the face of widespread tax evasion fostered by 1,800 Credit Suisse employees serving U.S. clients. The firm also misled investors about growth in its private banking unit, according to the report. The Justice Department has failed to use all its legal tools in its criminal probe of whether Credit Suisse, the second-largest Swiss bank, helped U.S. clients evade taxes, according to the report. Lax enforcement also allowed Credit Suisse to turn over the names of only 238 U.S. account holders to prosecutors, the report said.