- Video report by ITV News Business Editor Joel Hills
The Queen's private estate has reportedly been found to have millions of pounds invested in offshore tax havens.
It is alleged that the Duchy of Lancaster, which handles the Queen's investments, has held funds in the Cayman Islands and Bermuda.
Around £10 million of the Queen's private cash is said to have been tied up in offshore portfolios, it is claimed.
The revelations come as some 13.4 million financial documents - dubbed the Paradise Papers - relating to the tax affairs of some of the world's richest people were analysed by media organisations.
Other household names cited in the papers include F1 world champion Lewis Hamilton, who reportedly bought his private jet through a series of offshore companies reclaiming £3 million in VAT in the process.
His lawyers insist the tax structure used was lawful.
Meanwhile, tech giant Apple is alleged to have secretly moved part of its controversial tax structure to the Channel island of Jersey - a move the company says is legal.
Labour leader Jeremy Corbyn has called for an "immediate public inquiry" into the claims.
But Theresa May has refused to commit to a formal probe or to introducing a public register of who owns offshore companies and trusts in British tax havens, saying only that people should "pay the tax that is due".
Asked if the Queen should apologise, Mr Corbyn told the CBI's annual conference in London: "Anyone that is putting money into tax havens in order to avoid taxation in Britain... should do two things - not just apologise for it but also recognise what it does to our society.
"Because if the very wealthy person wants to avoid taxation in Britain and therefore put money into a tax haven somewhere, who loses?
"Schools, hospitals, housing, all those public services lose and the rest of the population have to pay to cover up the deficit created by that."
He added: "We simply need to challenge the culture that it is somehow clever to avoid taxation.
"It undermines every one of us who pays our taxes properly and diligently. It must stop."
Around £10 million from the Queen's private fund was paid into funds in the Cayman Islands and Bermuda between 2004 and 2005, according to reports.
A small portion of the Queen's cash - £3,208 - was found to have bought a holding in the lender BrightHouse, it is claimed.
The rent-to-buy firm has previously been accused of ripping off customers with high interest rates, but maintains it does responsible business.
A further £5 million was invested in 2004 in the Bermuda-based Jubilee Absolute Return Fund Ltd.
The Queen voluntarily pays tax on any income she receives from the Duchy.
A spokesman for the estate 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."
There is no suggestion that those involved acted illegally.
Political figures and celebrities are said to feature in the leaked papers, with stars of hit BBC comedy Mrs Brown's Boys among the latest named.
Paddy Houlihan, who plays Dermot in the show, Fiona O'Carroll, who plays Maria and Martin Delany who stars as Trevor, made use of a scheme that used trusts based in Mauritius and a series of loans and consultancy payments to reduce the tax they paid in the UK and Ireland, the Guardian reported.
Also among those said to be named in the papers are former Tory treasurer Lord Ashcroft.
He responded to the claims made in the BBC's Panorama programme on Twitter writing: "I can state unequivocally that I have not ignored rules...and never have done."
U2 frontman Bono is among a raft of celebrities said to be named in the Paradise Papers.
The singer - whose real name is Paul Hewson - allegedly used a Malta-based company to pay for a share in a shopping centre based in Lithuania.
A spokesman for the singer told the Guardian the star was a "passive, minority investor in Nude Estates Malta Ltd, a company that was legally registered in Malta until it was voluntarily wound up in 2015."
The revelations are not the first time the tax arrangements of Bono have come under scrutiny; in 2009 he was accused of storing his wealth in a Dutch tax haven.
US president Donald Trump's commerce secretary, Wilbur Ross, who is reportedly linked to a Russian firm, was also named in the papers.
He is allegedly shown to have cash in a shipping company which deals with Russian leader Vladimir Putin's son-in-law.
The Russian firm navigator, in which the offshore investments are reportedly held, has a partnership with Sibur, a gas company co-owned by Kirill Shamalov, who is married to Mr Putin's daughter.
The leak comes one year after the disclosure of the Panama Papers sent shockwaves through the world of business.
Two offshore service providers are said to be the source of the material, along with the company registries of 19 tax havens.
First obtained by the German newspaper Suddeutsche Zeitung, the documents have reportedly been analysed by almost 100 media organisations.
The International Consortium of Investigative Journalists oversaw the project, it is claimed.
Hundreds of individuals and companies reportedly have their overseas tax affairs laid bare in the papers.