Jeremy Corbyn has suggested the Queen, among others, should apologise for using overseas tax havens if they were used to avoid taxation in the UK.
The Labour leader was asked at the CBI conference whether the Queen should say sorry for making overseas investments.
He said anyone putting money into tax havens for the purposes of avoidance should “not just apologise for it, recognise what it does to our society”.
The BBC has revealed that the Queen’s estate has used overseas tax havens.
It comes after a leak from the tax haven of Bermuda revealed the secret overseas investments of the rich and famous, including the Queen.
Mr Corbyn’s spokesman later clarified his comments, saying the Labour leader did not specifically call on the Queen to apologise – but thought “anyone who puts money into a tax haven to avoid paying tax should acknowledge the damage it does to society”.
Buckingham Palace has not commented on the revelation that the Duchy of Lancaster, which handles the Queen’s private wealth, used offshore investments.
A spokesperson for the Duchy of Lancaster said: “We operate a number of investments and a few of these are with overseas funds. All of our investments are fully audited and legitimate.
“The Queen voluntarily pays tax on any income she receives from the Duchy.”
A Downing Street spokesperson said HM Revenue and Customs had asked to see the leaked Paradise Papers.
Mr Corbyn called for a full enquiry, public lists of company ownership, and a new tax enforcement unit to tackle tax evasion.
Theresa May said efforts are already underway to raise tax haven revenues.
Mrs May’s spokesperson told reporters: “It is important to point out that holding investments offshore is not an automatic sign of wrongdoing, but HMRC (Her Majesty’s Revenue and Customs) has requested to see the papers urgently so it can look into any allegations.”
Earlier, at the CBI conference, the prime minister did not commit to a public inquiry into tax revenue lost through offshore tax havens.
She also did not directly answer when asked whether she would insist on British overseas territories publishing a list of who owns companies and trusts they have registered.
Plans for a publicly available register were abandoned by former Prime Minister David Cameron after overseas territories lobbied against it, according to Liberal Democrat leader Sir Vince Cable.
Mrs May said HMRC had collected £160bn by tackling tax avoidance, evasion and non-compliance since 2010.
She added the UK government was working with the overseas territories “to ensure we’re seeing greater transparency”.
“We want people to pay the tax that is due,” she said.
The premier of Bermuda said the investments were legal, and the UK bore ultimate responsibility for the rules.
On Sunday, BBC Panorama broadcast the first results of its year-long investigation into the Paradise Papers, a massive leak of financial documents from Bermuda-based law firm Appleby.
Labour Party leader Jeremy Corbyn said the proliferation of British tax havens was “a leach on our public services by the super-rich elite”.
He said Paradise Papers was “socially damaging” and a “costly scandal” that needed to be tackled directly by the UK government.
Mr Corbyn called for a full public inquiry in to the use of overseas tax havens, as well as a public list of company ownership, an idea first mooted by former business secretary Sir Vince Cable.
Sir Vince criticised the government for not clamping down on offshore tax havens trading under the British flag.
The Paradise Papers leaks have raised questions over the investments of Conservative Party donor Lord Ashcroft, Everton FC owner Farhad Moshiri, and offshore investments made on the Queen’s behalf by the Duchy of Lancaster.
Sir Vince said: “The Paradise Papers suggest that a small number of wealthy individuals have been able, entirely legally, to put their money beyond the reach of the Exchequer.”
Sunday’s edition of Panorama reported that former Conservative Party chairman Lord Ashcroft remained a non-dom, and continued to avoid tax despite attempts to make peers pay their full share.
The leaked documents show that between 2000 and 2010, Lord Ashcroft received payments of around $200m (£150m) from his offshore trust in Bermuda.
Lord Ashcroft said he would not comment on the allegations because of the way he had been treated by BBC Panorama in the past.
Sir Vince said: “Given these revelations, including news that Conservative donors benefited from these arrangements, we need a parliamentary select committee to investigate fully who decided what and why.”
He also criticised Mr Cameron, after the government backed down from developing a company register for British overseas territories.
He said: “David Cameron was initially attracted to the idea [of a register], but when the overseas territories said on a visit to London that they were against it, he backed down.”
Shadow chancellor John McDonnell has called for a full register of companies, who owns them and who the beneficiaries are, to see how much tax is being lost through offshore tax havens.
The Paradise Papers puts into question the practise of using highly secretive offshore tax havens, which is legal.
The premier of Bermuda David Burt said Bermuda has a “robust regulatory regime” and it has had the same tax system since 1898. He added the UK’s tax law allows the use of offshore tax havens.
The papers are a huge batch of leaked documents mostly from offshore law firm Appleby, along with corporate registries in 19 tax jurisdictions, which reveal the financial dealings of politicians, celebrities, corporate giants and business leaders.
The 13.4 million records were passed to German newspaper Süddeutsche Zeitung and then shared with the International Consortium of Investigative Journalists (ICIJ). Panorama has led research for the BBC as part of a global investigation involving nearly 100 other media organisations, including the Guardian, in 67 countries. The BBC does not know the identity of the source.
Paradise Papers: Full coverage; follow reaction on Twitter using #ParadisePapers; in the BBC News app, follow the tag “Paradise Papers”
Watch Panorama on the BBC iPlayer (UK viewers only)