Swiss banks violated the law by passing banking information on to the U.S. Central Intelligence Agency, the country's top data protection official said Friday.
The banks, usually known for safeguarding the privacy of their clients, should have informed customers making international money transfers via the Belgium-based SWIFT money-transfer service that their data could be passed on to third parties, Hanspeter Thuer said.
Just the possibility of the data being leaked should have been grounds enough to warn customers, he said.
After the Sept. 11 attacks, SWIFT largely complied with U.S. requests for banking information in its anti-terror investigations.
SWIFT, or the Society for Worldwide Interbank Financial Telecommunication, operates a secure electronic messaging service used by some 7,800 financial institutions to make international money transfers worth $6 trillion a day.
Thuer said the issue was whether information could be passed on to states whose data protection laws are not as stringent as those in Switzerland.
Referring to a report by a Belgian privacy commission, Thuer urged that a solution be negotiated by which U.S. laws and European data protection rules are standardized.
Last month, Switzerland Finance Minister Hans-Rudolf Merz said giving the CIA access to the SWIFT information did not infringe Swiss sovereignty or the country's banking secrecy rules.