In the wake of leaked Panama Papers campaigners have called for a crackdown on tax havens linked to the United Kingdom.
Here we look at some of the main British Overseas Territories and Crown Dependencies that are among the so-called treasure islands.
1. Channel Islands - 1,800 offshore companies
Mossack Fonseca lists Jersey and Guernsey as among its offices internationally.
2. Isle of Man - 5,000 intermediaries
No capital gains, wealth, stamp duty, or inheritance tax - its government describes it as 'low tax jurisdiction'.
3. Cayman Islands - undisclosed
The Caribbean islands boast no income, corporate, sales, capital gains, wealth, inheritance or property taxes. Secrecy is also one of its selling points.
4. British Virgin Islands - 113,000 companies, 32,000 inhabitants
The Panama Papers reveal that half of the companies that appear in Mossack Fonseca's files were incorporated in the British Virgin Islands.
The Panama Papers have been described as the world's biggest data leak. The information came from 11.5 million files from Mossack Fonseca, which is the fourth biggest offshore law firm in the world, the Guardian reports. The data essentially shows how some of the world's rich and famous have been taking advantage of offshore tax initiatives.
The PM has stepped down from his position after the Panama Papers revealed that he had been sheltering money offshore.