More than 2,400 people have registered to disclose unpaid tax since the Liechtenstein Disclosure Facility was signed three years ago, with £363m already paid in tax bills. The revenue body believes the agreement over the tax haven, which was predicted to raise £1bn, will produce up to £3bn because more people have come forward than anticipated.

Some 5,000 Britons are believed to have hidden money in secret accounts in Liechtenstein and the deal allows investors who are liable to pay UK tax to “legitimise” their past tax affairs. People who own up to what they have done could face penalties amounting to only 10 per cent of the tax they have evaded, although they will still have to pay back taxes and interest going back up to 10 years.

Tax dodgers who fail to come forwards face tougher fines of up to 200 per cent of their unpaid tax, as well as back taxes and interest, and in the most serious cases, prosecution.

Dave Hartnett, permanent secretary for tax at HMRC, said the LDF had been an “overwhelming success”.

The agreement was originally due to run to March 2015, but has been extended to April 2016.