Biggest leak in the history of data journalism just went live, and it's about corruption. https://t.co/dYNjD6eIeZ pic.twitter.com/638aIu8oSU — Edward Snowden (@Snowden) April 3, 2016

Russia's President Vladimir Putin has called on his citizens to bring all their offshore wealth back into the country, but he has sat least $2 billion in wealth squirreled away overseas, The Guardian reports.Putin keeps the money in the hands of his friends, but has access to anything he wants, the newspaper reports.The information comes from a leak of millions of papers from Mossack Fonseca, the fourth largest offshore law firm in the world. They were obtained more than a year ago by Sueddeutsche Zeitung, a newspaper in Munich, Germany, and shared with other media outlets.The documents go far beyond Putin, and include data on 72 sitting or former world leaders, USA Today reports.Edward Snowden, the former CIA worker who leaked a cache of data in 2013, tweeted Sunday in support of the massive Panama Papers leak.The leaked papers include details on offshore companies linked to families and associates of former Egyptian President Hosni Mubarak, Syria's President Bashar Assad, and the late Moammar Gadhafi of Libya.Though using offshore companies is not necessarily illegal, transactions in the leaked data indicate share deals that appear to be fake, fees for vague "consultancy" services and more, according to the Guardian. Shell companies also appear to have been set up in the British Virgin Islands.Putin's best friend, Sergei Roldugin, shows up in what are referred to as the Panama Papers. Roldugin, a musician, has grown extremely wealthy despite claims not to be a businessman. But the documents reveal he owns parts of several companies as well as a 3.2 percent stake in Bank Rossiya.That bank is lead by Yuri Kovalchuk, whom the United States says is the "personal banker" of several high level Russian officials, including Putin.Rodulgin declined to comment, saying only, "These are delicate issues. I was connected to this business a long time ago. Before 'perestroika.' It happened … And then it started growing and such things happened. The House of Music [in St Petersburg] is subsidized from this money."Putin's spokesman, Dmitry Peskov, also declined comment to the Guardian. Last week, he blamed spy agencies in the West for an "information attack" intended to destabilize Russia ahead of its elections.The United States imposed sanctions on top members of Putin's inner circle in 2014 after Russia invaded Crimea because it had information Putin was holding his wealth in the hands of his friends.