The International Consortium of Investigative Journalists collaborated with The Guardian and the BBC in Britain, Le Monde in France, Suddeutsche Zeitung and Norddeutscher Rundfunk in Germany, The Washington Post, the Canadian Broadcasting Corp. and 31 other news organizations to analyze the data from 2.5 million documents related to more than 120,000 offshore companies and trusts.
"The leaked files provide facts and figures -- cash transfers, incorporation dates, links between companies and individuals -- that illustrate how offshore financial secrecy has spread aggressively around the globe, allowing the wealthy and the well-connected to dodge taxes and fueling corruption and economic woes in rich and poor nations alike," the ICIJ said in its report, "Secrecy for Sale: Inside the Global Money Maze."
The group said the leak was much larger than the 2010 leak of U.S. State Department cables to Wikileaks.
Arthur Cockfield, who teaches law and taxation at Queen's University in Ontario, compared the data release to the scene in "The Wizard of Oz" where the curtain is pulled back.
"I've never seen anything like this. This secret world has finally been revealed," he said in a CBC interview.
Users of offshore tax havens range from Greek villagers to doctors and dentists in the United States to Russian billionaires, the ICIJ said. They include the oldest daughter of former Philippines President Ferdinand Marcos, the beneficiary of a trust in the British Virgin Islands, and the daughters of Ilham Aliyev, president of Azerbaijan.
"There will be people all over the world today who are now scared witless," Richard Murphy, research director for Tax Justice Network in Britain, told The New York Times.