HM Revenue & Customs (HMRC) could raise hundreds of millions of pounds from the probes, which were launched after the details of 7,000 British clients were passed to the UK, but a spokesman declined to comment on the figures involved.
A series of household names from Britain feature on the list, which includes high-earning UK citizens holding chunks of their wealth offshore, it is believed. HMRC yesterday confirmed it had received the information and intends to act upon it.
The disk was given to the French authorities and is said to contain the names of 79,000 HSBC clients in 180 countries.
Four years ago Hervé Falciani, a computer specialist who worked for HSBC in Geneva, leaked the data to French officials, who passed it onto the UK.
France later returned the files to Switzerland and copies of a “significant portion” of the missing data were handed back to HSBC early last year.
No-one from the bank could be contacted yesterday but it has previously said it does not condone tax evasion or help it to be carried out.
It comes just weeks after the UK and Switzerland agreed a separate deal that will see more than 15,000 British holders of Swiss bank accounts pay up to £5bn in tax.
Funds held by UK taxpayers in Switzerland will be subject to a one-off levy of between 19 per cent and 34 per cent, depending on the amount kept in the account.