The US president has announced changes to the law aimed at tackling tax evaders who use offshore accounts.
President Barack Obama has outlined plans to tackle the issue of tax havens through a series of tax law changes.
Speaking in Washington, the US president made clear during his election campaign that he would attempt to deal with tax havens and offshore accounts. He was also part of the G20 summit which announced a crackdown on Switzerland and other havens.
"On the campaign, I used to talk about the outrage of a building in the Cayman Islands that had over 12,000 businesses claim this building as their headquarters," said Mr Obama. "Either this is the largest building in the world or the largest tax scam in the world. And I think the American people know which it is."
Mr Obama will focus on targeting citizens in his own country who use offshore accounts to hide their money from the US treasury. The UK could follow suit, with the prime minister last month writing to Crown dependencies and offshore territories such as the Channel Islands, Bermuda and Gibraltar - as well as the Cayman Islands - urging them to become more transparent with tax dealings.
Gordon Brown told the territories involved last month that they would have six months to adhere to international standards or they would face sanctions.
