Image copyright David Rogers

Foreign firms that own property in the UK will have to declare their assets publicly in a bid to stamp out money-laundering, the government says.

Companies will have to be on a new register if they hold property or want to compete for government contracts.

The move comes as Prime Minister David Cameron attempts to lead a wider effort to crack down on global corruption.

World leaders are gathering in London for a summit aimed at stepping up action to tackle the problem.

Funds 'siphoned'

Downing Street said Mr Cameron's plans for a register of foreign companies owning UK property would include those who already owned property in the UK as well as those seeking to buy.

It said the register would mean "corrupt individuals and countries will no longer be able to move, launder and hide illicit funds through London's property market, and will not benefit from our public funds".

Media playback is unsupported on your device Media caption David Cameron on 'fantastically corrupt' countries attending a UK anti-corruption summit

It said foreign companies owned about 100,000 properties in England and Wales and that more than 44,000 of these were in London.

Tax havens

Mr Cameron will also say that some of Britain's overseas territories and crown dependencies will join 33 other countries in agreeing to share automatically their own registers of company ownership, information that will be accessible to the police.

Matthew Hancock, Cabinet Office Minister, told the BBC: "It does not matter where in the world your company is registered if you own property in London or sell things to government, as part of government procurement, then you have to declare the beneficial ownership, in other words the ultimate ownership of the company."

Mr Cameron will also announce plans for a new anti-corruption co-ordination centre in London and a wider corporate offence for executives who fail to prevent fraud or money laundering inside their companies.

"Corruption is the cancer at the heart of so many of our problems in the world today," Mr Cameron wrote in the Guardian ahead of the summit.

"It destroys jobs and holds back growth, costing the world economy billions of pounds every year.

"It traps the poorest in the most desperate poverty as corrupt governments around the world siphon off funds and prevent hard-working people from getting the revenues and benefits of growth that are rightfully theirs."

The head of the Cayman Islands' main finance organisation has questioned whether a public register of the owners of businesses in offshore centres would be effective.

Jude Scott, the head of Cayman Finance, told the BBC's economics editor, Kamal Ahmed, that they and the British Virgin Islands had already agreed to share such details with tax authorities and law enforcement bodies to tackle tax evasion and money laundering.

Mr Scott said the register would only be really effective if it was global and all G20 and international financial centres took part.

In an interview with the Financial Times on Wednesday, Wayne Panton, the Cayman Islands' financial services minister, said a public register would also only work if the information was verified.

He said the Cayman Islands had required company providers to collect and verify information for the past 15 years, but he ruled out putting it into the public domain.

'Battling hard'

The anti-corruption summit is being hailed as the first of its kind, bringing together governments, business and civil society.

It is being hosted by Mr Cameron. No full list of those attending the Lancaster House summit has been published, but participants will include US Secretary of State John Kerry, Nigerian President Muhammadu Buhari and Afghan President Ashraf Ghani.

No detailed agenda has been made public, but organisers say it will agree ways to "expose corruption so there is nowhere to hide".

The summit has already been overshadowed by controversy after it emerged that Mr Cameron had described Nigeria and Afghanistan as "fantastically corrupt".

Media playback is unsupported on your device Media caption Afghan president Ashraf Ghani says his country is "one of the most corrupt countries on earth"

He made the comment while talking to the Queen at Buckingham Palace and his words were caught on camera.

The PM later said the countries' leaders were "battling hard" to tackle the problem.

Tackling corruption

Asked ahead of the anti-corruption conference in London if Nigeria was "fantastically corrupt", President Buhari, who came to power last year on a promise to fight corruption, replied: "Yes."

Mr Buhari, speaking at a separate event hosted by the Commonwealth, said he was more interested in the return of stolen assets held in British banks, adding that corruption in Nigeria was endemic and his government was committed to fighting it.

Media playback is unsupported on your device Media caption President Buhari says "the scale of corruption is enormous" in Nigeria

Mr Hancock defended Mr Cameron's remarks.

"He [President Buhari] said the Prime Minister was telling the truth and the reason the President of Nigeria has come to this summit is because he is fully committed to tackling corruption in Nigeria. Indeed he won an election based on tackling corruption".

Mr Hancock said it was up to countries such as the UK to work with developing nations to make sure money taken from them is not hidden in assets in capital cities such as London.