HSBC Private Bank (Suisse) has confirmed that one of its former employees stole data which, according to reports, contains details on the accounts of alleged French tax evaders and is being used by the French government in its attempts to prise open the Alpine state’s famed banking secrecy practices.

Back in August, the French government said it had a list of some 3,000 of its citizens which it alleges have hidden assets in Switzerland, but it would seem that the data stolen from HSBC Private Bank’s Geneva branch would comprise only a very small part of such a list. “To the best of the bank’s knowledge, the number of names potentially involved is less than 10,” HSBC Private Bank said in a statement.

HSBC Private Bank said that the former employee, who worked in its IT-development group, was found to have stolen data between end of 2006 and early 2007. While a criminal enquiry by the Swiss authorities into the theft is ongoing, it is thought that the individual is now living in France under judicial protection. The Swiss take its banking secrecy laws very seriously and a banker who reveals client information without due cause can face a harsh fine, or even a prison term.

As governments struggle with spiralling debt in the wake of the financial crisis it would seem they are finding it easy to overcome any squeamishness over using using stolen data – and at least two are thought to have paid for such information to assist their efforts to claw back lost tax revenues.

At the end of last year reports emerged that both the UK and German tax authorities had bought bank records of a large number of individuals holding bank accounts at the LGT Bank in Liechtenstein.

The data was reportedly purchased from an ex-employee of the bank who had previously tried to use it to blackmail the Liechtenstein government.