British Prime Minister David Cameron acknowledged in a TV interview on Thursday that he once had a stake in his late father's offshore trust, which was revealed in the "Panama Papers" leak from a law firm.

Cameron told ITV News that he had owned shares in the Panamanian trust, Blairmore, but had sold them in 2010, before becoming prime minister.

"We owned 5,000 units in Blairmore Investment Trust, which we sold in January 2010. That was worth something like £30,000," he told the television channel.

"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 said.

Cameron was expected to publish his tax returns as soon as possible, Sky News said in a tweet.

Cameron's late father, Ian, was among tens of thousands of people named in leaked documents from Panama law firm Mossack Fonseca which showed how the world's rich and powerful stash their wealth..

The firm specialises in establishing offshore companies, which could be used to avoid taxes, but there are several legitimate reasons for individuals and corporations to set them up.

In a statement on Tuesday, a spokesman for Cameron said that the prime minister, his wife and their children did not benefit from any offshore funds at present.

On Wednesday, a spokesman for Cameron said: "There are no offshore funds or trusts which the prime minister, Mrs Cameron or their children will benefit from in future."