Hong Kong companies were used by Credit Suisse to help US taxpayers avoid taxes, a report by the US Senate's Permanent Subcommittee on Investigations found.
The bank discovered its Swiss-based bankers "were well aware that some US clients wanted to conceal their accounts from US authorities, and either turned a blind eye to the accounts' undeclared status, or actively assisted those account holders to hide assets from US authorities", the report said.
Credit Suisse said it acknowledged misconduct "centred on a small group of Swiss-based private bankers". "While that employee misconduct was unknown to our executive management, we accept responsibility for and deeply regret these employees' actions," it said.
The bank said it had provided US client information to the US authorities "to the full extent allowed by Swiss law", and was ready to provide more information but was unable to do so, because the US Senate had not ratified a double-taxation treaty between Switzerland and the US.
The Senate report pointed to the case of a former Credit Suisse US account holder, Jacques Wajsfelner, who used a trust expert of the bank, Beda Singenberger, to form a Hong Kong company, Ample Lion, in 2006, with Wajsfelner as the sole beneficial owner and Singenberger as the nominal corporate director. Singenberger assisted Wajsfelner in opening an Ample Lion bank account at Credit Suisse that contained nearly US$5.7 million at the end of 2007.
Wajsfelner was sentenced to six months' probation for failing to file information on his Swiss bank accounts to the US Internal Revenue Service (IRS) and was also ordered to pay US$74 million to the US government.
"By opening the Ample Lion account at Credit Suisse, Wajsfelner was attempting to obscure his ownership of the assets in the account from the IRS," the US Department of Justice said.