The BBC is to reveal the names of wealthy businessmen it claims have opened offshore Swiss bank accounts without informing the UK tax authorities.

The Panorama special edition is set to expose how HSBC helped up to 400 of its wealthiest customers avoid the taxman.

All the names are understood to have come from a computer disc stolen from the banking giant's Geneva office by a whistleblower and relate to its Swiss subsidiary HSBC Private Bank.

The disc, understood to contain the names of 24,000 clients, was leaked by 43-year-old IT and systems engineer Herve Falciani in 2007, who claimed the way some data was managed at Britain's biggest bank would help tax evaders. He said his suggested reforms were rejected by bosses.

Some of the data has since been passed to France, Italy, Spain and Germany, which have pursued claims for up to £180 million in lost revenue.

Four years ago, HMRC targeted some 6,000 UK-based Swiss bank account holders who may not have declared income and gains from foreign accounts.

Officials secured their first high-profile prosecution using details from the disc in 2012 after Berkshire property developer Michael Shanly was estimated to have evaded some £430,000 in inheritance tax.

The latest purge by the taxman - and due to be exposed by Panorama - is said to involve a list of 400 high-profile businessmen. 

According to a source they were first approached by 'aggressive' letters some weeks ago asking for their comments on Swiss accounts they held.

'The letters suggested a deadline for a response before the programme is broadcast,' explained the source.

Last night a spokesman for HSBC declined to comment on the stolen disc and the latest moves by the taxman to use information from the bank's records.

Panorama: The Bank of Tax Cheats will be shown at 8.30pm on Monday.