HSBC's Swiss wealth management unit, which is based in Geneva, is the first Swiss bank to confirm the theft of a CD containing information on 24,000 clients, mainly from France.

HSBC did not say whether the disc had data from clients in other countries. When the French authorities got hold of the CD in December, HSBC originally made light of the situation and said the data concerned only a very small number of people.

Switzerland under pressure

Several other CDs with stolen data have been handed in to authorities in Germany.

The state of North-Rhine Westphalia recently purchased a CD for 4.5 million euros ($6.1 million) believed to contain tax data from 1500 clients of Swiss bank Credit Suisse. But the bank has repeatedly said there were no indications information had been copied illegally.

Switzerland has come under pressure to change its client protection rules, which are widely seen as too secretive by other European countries and the US.

The debate about banking secrecy laws kicked off two years ago, when data was stolen from a bank in Liechtenstein, which has also been accused of being too secretive about banking clients. The German government decided to buy the CD, which sparked a spat between Germany and Switzerland and led to demands for more transparency.

ng/Reuters/dpa
Editor: Rob Turner