More than 100 wealthy Australians, some of them high-profile, have netted tens of millions of dollars in ill-gotten gains through newly discovered links to a worldwide network of tax havens, the Tax Office claims.

ATO deputy commissioner of serious non-compliance Greg Williams said two Australians were under criminal investigation, while 65 others had been identified as ''high risk'' because they had each moved more than $1 million in or out of Australia without declaring the money in their tax returns.

The ATO will look into cash movements. Credit:Gabriele Charotte

The swoop is based on a database - obtained through the ATO's international information exchange network - of more than 2 million documents that show how thousands of people around the world use shell companies and trusts in tax havens Singapore, the British Virgin Islands, the Cayman Islands and the Cook Islands.

Mr Williams said he expected the number of Australians caught up in the probe to grow as the ATO swaps intelligence with its US and British counterparts.