A major international leak of more than 13 million files - known as the Paradise Papers - reveal how the super-rich invest vast amounts of money in offshore tax havens.
Some of the main findings are that Donald Trump's commerce secretary has ties to allies of Russian President Vladimir Putin, and that the Queen of England has invested about $13m in private money offshore.
The vast tranche of leaked financial documents have been analysed by media organisations, including the BBC and The Guardian.
It is alleged that the Duchy of Lancaster, which handles the Queen of England's investments, has held funds in the Cayman Islands and Bermuda. The Queen voluntarily pays tax on any income she receives from the Duchy.
Around $13m of the Queen's private cash is said to have been tied up in offshore portfolios, the BBC reports. There is nothing to suggest that any investments are illegal, the broadcaster added.
Around 13.4 million files are said to have been involved in the leak, which 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.
US President Donald Trump's commerce secretary, Wilbur Ross, 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 Paradise Papers allegedly reveal that several major global companies have been exploiting offshore schemes to avoid tax.
CEO of Oxfam Ireland Jim Clarken said the leak shows governments are losing billions through tax-scams around the globe.
He said: "The Paradise papers are yet another ugly insight into how the global tax system is being exploited by those who should be paying most. They reveal the staggering scale of the tax dodging scams and evasion tricks which are depriving governments of billions in income.
"The revelations in the Paradise Papers also expose our leaders’ feeble attempts to stop tax cheats. Following the Panama Papers expose, we heard tough talk from politicians but this has translated into weak reforms thanks to pressure from big business and the super-rich.
"We must remember that tax dodging impacts on everyone whether they live in richer nations or the developing world. It fuels poverty and inequality. When the super-rich and corporations dodge taxes it is ordinary people, who pay the price."
Oxfam Ireland is proposing several ways to stop the global tax dodging, including the establishment of a "blacklist" of countries that refuse to adhere to international taxation rules, where listed countries would face stiff penalties; setting up a publicly-available register of companies so we know who their real owners are and introducing a second round of tax reforms to build on the BEPS1 (Base Erosion and Profit Shifting) process.
"This time it should work in favour of all countries, not just the wealthiest," Oxfam said.