The HMRC's investigation is based on information from an informant
The UK's tax authority may prosecute about 300 wealthy Britons with accounts in Liechtenstein as part of a tax evasion investigation.
HM Revenue & Customs (HMRC) says it hopes to recover about £300m in unpaid taxes from those who have stashed away more than £1bn in the Alpine tax haven.
Some of those under investigation may settle out of court, HMRC said.
Germany, the US and other countries are also looking at Liechtenstein account holders in a tax evasion crackdown.
Paul Franklin, a spokesman for HMRC, said those found to have evaded taxes must pay the amount they owe plus interest and a penalty of up to 100% of the unpaid tax.
"We're dealing with very wealthy people who have used Liechtenstein's secrecy laws to escape UK tax regulations," he said.
In certain circumstances, those found guilty of tax evasion can face a prison sentence of up seven years.
The investigation is expected to be completed within three years.
The investigation is based on data obtained from a paid informant who once worked for Liechtenstein's LGT Bank
The informant also sold information to Germany and other tax authorities.
The Organisation for Economic Co-operation and Development (OECD) lists Liechtenstein as one of only three states remaining on its blacklist of "unco-operative tax havens".
HMRC is also launching a wider investigation into offshore accounts.