HMRC is working with the United States and Australia to analyse 400 gigabytes of data showing the use of tax evasion schemes via companies and trusts in territories around the world including Singapore, the British Virgin Islands, the Cayman Islands and the Cook Islands.
It is understood to be the biggest tranche of information ever received by HMRC about offshore tax evasion and it has so far identified more than 100 people who are benefiting from these tax evasion schemes, with a number of individuals already being investigated.
HMRC has also identified more than 200 UK accountants, lawyers and other professional advisers who advise on setting up these structures who will also be scrutinised.
It is calling on anyone using offshore tax schemes to seek advice to ensure they are not breaking the law, which can result in criminal prosecution, hefty fines and possible naming and shaming.
Chancellor George Osborne said: "The message is simple: if you evade tax, we're coming after you.
The Association of Chartered Certified Accountants (ACCA) said while it welcomed moves to clamp down on tax evasion, "we should never lose sight of the fact that it is a small number of people who are evading tax in these markets".
Chas Roy-Chowdhury, head of taxation at ACCA, added: "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."