The UK's HM Revenue and Customs is working with the US and Australian tax administrations to investigate hundreds of accountants, lawyers and other professional advisors as part of its ongoing crackdown on offshore tax evasion.

The three countries have obtained a substantial amount of data which reveals extensive use of complex offshore structures to conceal assets held by wealthy individuals and companies.

The data contains 400GB of information which is still being analysed. Early results show the use of companies and trusts in Singapore, the British Virgin Islands, the Cayman Islands, and the Cook Islands, HMRC said in a statement.

So far, 100 people benefiting from these schemes have been identified, a number of whom are already being investigated, HMRC said.

More than 200 UK accountants, lawyers and other professional advisors involved have also been identified and will be scrutinised.

The agencies said they planned to share information that is relevant with other jurisdictions if requested and encouraged taxpayers with undisclosed assets to come forward.

“Working with the international tax community to pursue offshore evasion is another important step in closing the net on tax evasion," said Jennie Granger, HMRC commissioner.

"There is nothing illegal about an international structure, especially in a globally integrated economy and these arrangements may be perfectly legitimate and may already have been declared to HMRC. However, they may involve tax evasion, avoidance or other serious offences by taxpayers. What has to stop is using offshore structures to illegally hide assets and income," she added.

In other recent news, last week several overseas territories said they had agreed to help the UK government's ongoing fight to clamp down on tax evasion by sharing bank account information held in their jurisdictions. For more on this story, click here.