BBC’s Panorama has seen accounts from over 100,000 clients in 203 countries that were originally leaked by Herve Falciani in 2007.
Of the 106,000 clients, 7,000 of them were from the United Kingdom.
HSBC stated that it was “accountable for past control failures.” But it has now “fundamentally changed”.
It added: “We acknowledge that the compliance culture and standards of due diligence in HSBC’s Swiss private bank, as well as the industry in general, were significantly lower than they are today.”
The bank is now under investigation in France, Argentina, Belgium and the US, but not in the UK where the company is based.
HSBC is now co-operating with the authorities in the relevant countries.
A joint investigation has begun after the documents were passed on to the International Consortium of Investigative Journalists, Panorama, the Guardian and over 50 more media outlets globally.
HM Revenue and Customs (HMRC) obtained the data in 2010 and identified 1,100 British clients of HSBC who had not paid taxes. After five years, only one person has been prosecuted.
According to the HMRC people who hid their money in Switzerland have paid £135 million in penalties, tax and interest.
But Margaret Hodge MP, Public Accounts Committee’s chairwoman said: “I just don’t think the tax authorities have been strong enough, assertive enough, brave enough, tough enough in securing for the British taxpayer the monies that are due.”