UK clients of HBSC Private Bank in Switzerland are the focus of an investigation by the tax authorities in the UK for having evaded a total of more than £200 million ($314 million) in tax, according to The Observer.

HMRC received data in 2010 smuggled out of the UK-owned Swiss bank by a former IT worker that included details of 6,000 people, companies and trusts with UK links. Last week, it emerged that Spain has been asked by the Swiss authorities to extradite Herve Falciani, the ex-IT worker who stole the data.

Banking secrecy is a constitutional right in Switzerland, but the tradition is under heavy pressure from revenue-hungry foreign governments, led by the US. Big fines imposed on some of the biggest banks in the country have meant that many of them are now turning away offshore assets.

HMRC told WealthBriefing that it did not recognise the figures in The Observer. The tax authority also said that the investigation is focused on the individuals involved rather than HSBC.

HSBC declined to comment when contacted by this publication besides saying that the bank does not condone tax evasion.

Meanwhile, HSBC has been in the headlines for the wrong reasons on several occasions lately. When publishing its financial results for the first half of 2012 yesterday, it said it has set aside $700 million for potential fines after anti money-laundering control failings in the US, as well as $1.3 billion for remedies related to the mis-selling of payment protection insurance and interest rate swaps in the UK market.