British property is a safe haven for money stolen from around the world, with tens of thousands of London properties owned by secretive companies, according to a corruption report.
Campaign group Transparency International found 36,342 properties in London covering 3.6 square kilometres are held by companies registered in offshore secrecy havens such as the British Virgin Islands, Jersey and the Isle of Man.
Almost one-in-10 properties in the district of Westminster, where the British government is based, are owned by a company registered in an offshore haven, the report found.
In 2011 alone, the report said, STG3.8 billion ($A7.4bn) worth of UK property was bought by companies registered in the British Virgin Islands.
The group said the use of British property to store stolen wealth may have helped inflate prices - an explosive political issue due to near-record prices and a lack of affordable housing ahead of Britain's May election.
"There is growing evidence that the UK property market has become a safe haven for corrupt capital stolen from around the world, facilitated by the laws which allow UK property to be owned by secret offshore companies," said Transparency International executive director Robert Barrington.
"This has a devastating effect on the countries from which the money has been stolen, and it's hard to see how welcoming in the world's corrupt elite is beneficial to communities in the UK."
The group urged the government to make the Land Registry require transparency over who owners of companies are, in order to ensure Britain is not "the destination of choice for global corruption".