Police have raided the headquarters of the Panamanian law firm whose leaked Panama Papers revealed how the world's wealthy and powerful used offshore companies to stash assets.

Key points: Police raided the Mossack Fonseca "with no incident or interference"

Police raided the Mossack Fonseca "with no incident or interference" Company says it hasn't broken laws or destroyed any documents

Company says it hasn't broken laws or destroyed any documents China censoring online forums and media to stop names of relatives close to leadership circulating

Sorry, this video has expired Authorities raid law firm Mossack Fonseca

Police with an organised crime unit carried out the raid at Mossack Fonseca "with no incident or interference", prosecutors said in a statement, adding that searches would take place at the firm's Panama City headquarters and its branches.

Police officers and patrol cars began gathering around the company's building on Tuesday afternoon under the command of prosecutor Javier Caravallo, who specialises in organised crime and money laundering.

Mossack Fonseca, which specialises in setting up offshore companies, did not respond to requests for comment.

Earlier, founding partner Ramon Fonseca said the company had broken no laws, destroyed no documents, and all its operations were legal.

The Panama Papers, centred on a huge cache of documents pilfered digitally from the Mossack Fonseca, have had repercussions around the world.

Iceland's Prime Minister was forced to resign after his name appeared as one of the beneficiaries of an offshore company.

Britain's Prime Minister David Cameron has had to disclose his tax records.

Russian President Vladimir Putin has sought to divert attention from his entourage by claiming it is all a US plot against him.

China has been censoring online forums and media to try to prevent the names of relatives close to the leadership from circulating.

And wealthy citizens in Australia, France, India, Mexico, Peru, Spain and elsewhere face probes over suspected tax avoidance after their names figured in some of the 11.5 million documents.

Mr Cameron's image has taken a beating from the delay in revealing that he held shares in his late father's offshore fund and received money from his parents that may have skirted inheritance tax.

Sorry, this video has expired Explainer: Panama Papers

AFP