Credit Suisse said it has been asked to give account information to the Swiss Federal Tax Administration after US authorities requested Switzerland's help in catching suspected tax dodgers.

Earlier today, Reuters reported Credit Suisse had begun notifying certain US clients suspected of offshore tax evasion it intended to give their names to the SFTA following a request from the US Internal Revenue Service.

Credit Suisse and the State Secretariat for International Financial Matters (SIF) declined to say how many clients the request involved.

US authorities, which suspect tens of thousands of Americans of evading billions of dollars in taxes through Swiss private banks in recent years, have been conducting a widening criminal investigation into scores of Swiss banks, including Credit Suisse.

Mario Tuor, a spokesman for the SIF, confirmed the request from the US authorities, and said these requests specifically concerned tax fraud, which is covered by the 1996 double taxation treaty between Switzerland and the United States.

Switzerland and the United States are currently working on a tax agreement that would also cover tax evasion, but this has not yet been ratified.