Co-founder of Mossack Fonseca firm denies leak was an inside job, saying his company was victim of hackers from abroad.
British Prime Minister David Cameron has admitted he benefited from the offshore investment fund set up by his late father.
After days of pressure following the publication of the Panama Papers leak, Cameron said on Thursday he owned a stake in the Blairmore trust, which he sold in 2010 four months before taking office.
“We owned 5,000 units in Blairmore Investment Trust, which we sold in January 2010. That was worth something like £30,000 ($42,000),” Cameron told Britain’s ITV television.
“I sold them all in 2010, because if I was going to become prime minister, I didn’t want anyone to say you have other agendas, vested interests,” the Conservative leader added.
“I paid income tax on the dividends. There was a profit on it but it was less than the capital gains tax allowance, so I didn’t pay capital gains tax.”
Cameron’s late father, Ian, was among the tens of thousands of people named in the leaked documents from law firm Mossack Fonseca.
The revelations showed how the world’s rich and powerful are able to stash their wealth and avoid taxes.
After having at first described it as a private matter, Cameron’s office said on Tuesday that he and his family did not benefit from any such funds at present.
Cameron also said he did not own any shares or have any offshore funds.
But his failure to say whether he or his family would benefit in the future only intensified media speculation the following days, with the story splashed across many newspaper front pages on Wednesday.
“There are no offshore funds or trusts which the prime minister, Mrs Cameron or their children will benefit from in future,” the spokesperson said on Wednesday.
Cameron has cast himself as a champion in the fight against tax evasion, particularly in British-linked territories such as the British Virgin Islands and Cayman Islands.
However, the opposition Labour Party has said the Panama Papers show the government has failed to tackle the issue.
The International Consortium of Investigative Journalism, a non-profit group in the US, said the cache of 11.5 million records detailed the offshore holdings of a dozen current and former world leaders, as well as businessmen, criminals, celebrities and sports stars.
On Tuesday, Iceland’s Prime Minister Sigmundur Gunnlaugsson stepped down hours after thousands of protesters gathered outside parliament to demand his resignation following the Panama Papers investigation.
Elsewhere among sitting world leaders named in the leak are Argentine President Mauricio Macri and Ukraine’s President Petro Poroshenko.
The documents link at least 12 current and former heads of state and 143 other politicians to illicit financial transactions.