Britain took a significant step towards exposing dirty money in the London property market this week, passing a law allowing the seizure of homes from foreigners who cannot explain how they paid for them.
Anti-corruption campaigners hailed the "unexplained wealth orders" as a potentially game-changing tool to stop wealthy individuals from laundering their money through mansions in the affluent London boroughs of Knightsbridge and Hampstead.
The measure in the Criminal Finances Act, which became law on Thursday, will enable enforcement agencies to seize and if necessary then sell the properties, returning the funds to the country involved.
"If some corrupt official, who we know earns £30,000 ($39,000) or £40,000 a year, buys a house in the UK for £2 million there is unexplained wealth," said Margaret Hodge, an opposition Labour MP who campaigns on this issue.
In research published last month, campaign group Transparency International identified London properties worth £4.2 billion that it says were bought by individuals with suspicious wealth.
They should be "low-hanging fruit" for the new measures, said Duncan Hames, the group's director of UK policy.
"Any law is only as good as its implementation and we now call on law enforcement agencies to use unexplained wealth orders as soon as they are empowered to do so."
Naomi Hirst, senior campaigner at Global Witness, told AFP the orders could be "quite game-changing -- the caveat is that it is properly enforced".
The United States already has similar powers, and Matthew Page, a former US intelligence analyst who specialises in corruption in Nigeria, warned that its targets fight back with expensive lawyers -- and politics gets in the way.
"If the decision is made to go, say against Russia for other reasons, then it will be used. It's like these dogs they can unleash on these countries," he told AFP.
- 'Bad guys with money' -
Page was speaking on a special edition of London's "kleptocracy tours", which take visitors past homes allegedly bought with ill-gotten gains.
This week, campaigners used it to issue a string of mock unexplained wealth orders outside palatial houses in prime central London, mostly owned by Russian oligarchs.
Russia was the inspiration for another new power under the Criminal Finances Act, which enables British authorities to freeze the assets of foreign officials who abuse anti-corruption and human rights activists.
It followed a campaign in memory of late Russian lawyer Sergei Magnitsky, who was charged with tax evasion after revealing a massive fraud by state officials, and died in detention in 2009.
William Browder, a former Moscow financier turned anti-Kremlin campaigner who had employed Magnitsky, said Britain now had "extremely powerful new tools".
"I hope that the authorities start using these tools aggressively to show the world that London no longer is a safe haven for bad guys with blood money," he said.
"If nothing happens, we can draw our own conclusions."
- 'Reluctance to offend' -
Britain promised at an international summit in London in May 2016 to lead the global fight against corruption.
Since then, it has opened a public register showing who really owns and controls British companies, and this month launched a consultation on a similar register for overseas companies that own British property.
Campaigners have long called for improved transparency of ownership -- even if rich individuals increasingly use relatives or family friends to hide their purchases.
But the government has drawn fire for failing to include in this week's law measures to force registers on British overseas tax havens, through which many London property sales are routed via anonymous companies.
"Unless the next government legislates to stop anonymous overseas companies owning UK properties, we will continue to lose the fight against corruption," Hirst said.
Hodge accused Prime Minister Theresa May's government of holding back as it forges new global ties for when Britain leave the European Union.
"There's a reluctance to offend anyone, even the British Virgin Islands, if we think we can get some trade out of them," she said.