Offshore tax cheats face a clampdown from a new specialist investigations unit launched by HM Revenue and Customs (HMRC).
The new Offshore Co-ordination Unit (OCU) plans to focus on citizens who hide income and capital offshore to avoid UK tax and duties.
HMRC said the unit will look to fully exploit the "increasing amount" of offshore information at its disposal.
Exchequer Secretary to the Treasury David Gauke said: "The days when untaxed income or capital could be safely salted away offshore, beyond the reaches of the taxman, are long gone.
"The launch of this specialist unit, together with the other valuable work the department is driving forward in an effort to tackle offshore evasion, underlines the fact that offshore tax cheats are fast running out of places to hide."
The OCU will co-ordinate recently-announced investigations relating to HSBC's Geneva account holders.
Last month, HMRC said officials were targeting some 6,000 UK-based Swiss bank account holders in a clampdown on customers who may have failed to report all their income and gains.
The department is writing to residents and organisations holding accounts with HSBC in Geneva following information it received last year under a tax treaty. The information showed that more than 6,000 individuals, companies, trusts and other bodies held accounts and investments with HSBC Geneva.
The revenue and customs body has said it has already started criminal and serious fraud investigations into more than 500 people and organisations holding these accounts, and it is writing to people who have not yet come forward to give them a "window of opportunity".
If they fail to do so, HMRC said it will launch an investigation into their affairs, which could include a criminal investigation or result in penalties of up to 200% in some cases. The OCU is separate from the recently-announced Affluent Unit, which looks into land and property held offshore.
© 2011 Press Association