The British Prime Minister's father has been accused of running an offshore fund
Jeremy Corbyn has demanded an investigation into the tax affairs of Britons linked to the Panama leaks, including the Prime Minister's family.
The allegations in the Panama Papers have seen David Cameron dragged into a row about his late father's business affairs.
According to The Guardian, papers leaked from the Panama-based law firm Mossack Fonseca are said to suggest Mr Cameron's father Ian ran an offshore fund that avoided having to pay tax in Britain by hiring Bahamas residents to sign its paperwork.
Downing Street insists it was a "private matter" whether the Cameron family still had funds in offshore investments.
But while launching Labour's local elections campaign on Tuesday, Mr Corbyn told reporters: "It's a private matter in so far as it's a privately held interest, but it's not a private matter if tax has not been paid.
"So an investigation must take place, independent investigation, unprejudiced, to decide whether or not tax is owed ... I think the Prime Minister, in his own interest, ought to tell us exactly what's been going on."
The Labour leader said a probe by HM Revenue and Customs should be "about the amount of money of all people that have invested in these shell companies or put money into tax havens."
He said he also wanted UK tax officials "to calculate what tax they should have paid over the years."
Asked whether the PM should resign if he is found to have benefited, he replied: "Let's take one thing at a time. We need openness, we need an examination, we need a decision after that."
Pressed about his own taxes, Mr Corbyn said: "There is no problem with my tax affairs, they are very, very limited indeed. I have got an income as an MP, sadly I have got no family trusts of any sort."
Among the revelations in the Panama Papers is a network of secret deals and loans worth $2bn (£1.4bn) which apparently leads to Russian President Vladimir Putin.
Others said to be involved in the schemes include the prime ministers of Iceland and Argentina.