HM Revenue and Customs (HMRC) has launched a fresh crackdown on offshore tax evasion after analysing new data on the tax arrangements of individuals and companies.

HMRC is working with tax administrations in the United States and Australia to analyse 400GB of data that shows the extensive use of complex offshore structures to conceal assets by wealthy individuals and companies. The territories of most interest to HMRC are the British Virgin Islands, Singapore, the Cayman Islands and the Cook islands.

So far, HMRC has identified more than 100 people who benefit financially from tax evasion schemes, with a number of individuals already being investigated. It has also identified more than 200 UK accountants, lawyers and other professional advisers who give guidance on setting up these structures.

George Osborne, Chancellor of the Exchequer, said: "The message is simple: if you evade tax, we're coming after you. The government has invested hundreds of millions of pounds to fund the fight against tax evasion, both at home and abroad. This data is another weapon in HMRC's arsenal."

The Association of Chartered Certified Accountants (ACCA) said that, while it welcomes moves to clamp down on tax evasion, the government shouldn't lose sight of the fact that it's only a small number of people who are evading tax in these markets.

Chas Roy-Chowdhury, Head of Taxation at ACCA, said: "The majority of accountants, lawyers and other professional advisers, as well as their clients, are not breaking any laws in these locations.

"There is a large gulf between what amounts to tax avoidance, which is within the law, and tax evasion, which is illegal."

In March, HMRC published their No safe havens document, outlining the clampdown on offshore tax evaders. Measures will include banks collecting information on the offshore accounts of UK residents, encouraging disclosure, imposing sanctions, and prosecuting offenders.