The files leaked from Panama law firm Mossack Fonseca exposed Britain's link to thousands of firms based in tax havens and how secret money is invested in British assets, particularly London property.
Critics accuse British authorities of turning a blind eye to the inflow of suspect money and of being too close to the financial sector to clamp down on the use of its overseas territories as havens, with the British Virgin Islands alone hosting 110,000 of the Mossack Fonseca's clients.
"London is the epicentre of so much of the sleaze that happens in the world," Nicholas Shaxson, author of the book "Treasure Islands", which examines the role of offshore banks and tax havens, told AFP.
The political analyst said that Britain itself was relatively transparent and clean, but that companies used the country's territories abroad -- relics of the days of empire -- to "farm out the seedier stuff", often under the guise of shell companies with anonymous owners.
"Tax evasion and stuff like that will be done in the external parts of the network. Usually there will be links to the City of London, UK law firms, UK accountancy firms and to UK banks," he said, calling London the centre of a "spider's web".
"They're all agents of the City of London -- that is where the whole exercise is controlled from," Richard Murphy, professor at London's City University, said of the offshore havens.
The files showed that Britain had the third highest number of Mossack Fonseca's middlemen operating within its borders, with 32,682 advisers.
Although not illegal in themselves, shell companies can be used for illegal activities such as laundering the proceeds of criminal activities or to conceal misappropriated or politically-inconvenient wealth.
Around 310,000 tax haven companies own an estimated £170 billion (210 billion euros, $240 billion) of British real estate, 10 percent of which were linked to Mossack Fonseca.
The files appeared to show that the United Arab Emirates President Sheikh Khalifa bin Zayed Al-Nahyan owned London properties worth more than £1.2 billion and that Mariam Safdar, daughter of Pakistani prime minister Nawaz Sharif, was the beneficial owner of two offshore companies that owned flats on the exclusive Park Lane.
The revelations undermined promises by British Prime Minister David Cameron to clear up the murky world of offshore finance and its proceeds.
"Every few years London pretends to 'clean up its act'," wrote columnist Simon Jenkins in the capital's Evening Standard newspaper.
"Most world cities are ruthless against foreigners who arrive with suitcases of cash to buy property or other businesses. Not London," he added.
- AFP
