"The lack of compliance with data protection legislation may actually hamper consumers' trust in their banks and thus might also affect the financial stability of the payment system."

European data laws stipulate personal information must not be transferred out of Europe to countries with weaker data protection laws than Europe. The U.S. is considered such a country.

A statement on the Swift Web site says that a U.S. civil liberties panel, briefed on the issue on Tuesday November 28, said Swift had placed tight controls in place to protect data privacy. The issue, according to Swift is a "misinterpretation" of both U.S. and EU data protection laws.

"The panel was impressed with the lengths to which Swift had gone to prevent infringement on people's civil rights," the statement said.

"Swift has reiterated numerous times that it had gone beyond its legal obligations to ensure it complied with all laws, whether in the U.S. or EU.