Panama Papers: A Quick Guide to One of the Biggest Leaks in History

On Sunday, a massive leak dubbed the "Panama papers" revealed that some of the world's leaders, celebrities, and athletes have moved money to offshore accounts in order to hide their wealth and avoid taxes. Here's everything you need to know:

More than 11 million documents from the Panamanian law firm Mossack Fonseca show that powerful people across the world — including 12 current or former heads of state and at least 60 people associated with current or former world leaders — have laundered money and evaded taxes and sanctions through secret banks and offshore shell companies, according to the BBC.

The leak came after almost 400 journalists from more than 100 news organizations took part in an unprecedented, yearlong investigation that started when a German newspaper named Süddeutsche Zeitung received internal documents from an anonymous source. The International Consortium of Investigative Journalists published the findings along with the help of other media companies.

"The data includes emails, financial spreadsheets, passports and corporate records revealing the secret owners of bank accounts and companies in 21 offshore jurisdictions, including Nevada, Hong Kong and the British Virgin Islands," reads a statement about the Panama papers from the ICIJ.

The Panamanian law firm has sold thousands of fake companies for as low as $1,000. "However, at this price it is just an empty shell. For an extra fee, Mossack Fonseca provides a sham director and, if desired, conceals the company's true shareholder," reports the German paper Süddeutsche Zeitung. "The result is an offshore company whose true purpose and ownership structure is indecipherable from the outside."

Current leaders of Argentina, Iceland, Saudi Arabia, Ukraine, and Pakistan were among those implicated in the documents. So were friends and families of Syrian President Bashar Assad, former Egyptian President Hosni Mubarak, and former Libyan dictator Moammar Gadhafi. Russian President Vladimir Putin has come under major fire since the papers reveal his associates are suspected in a billion-dollar money-laundering scheme. You can get more details from Fusion, one of the media organizations that broke the news.

The documents also reportedly contain information about a former FIFA secretary general, FIFA presidential candidate, and a lawyer who advises FIFA on ethical issues. More recognized names are actor Jackie Chan, Bollywood star Amitabh Bachchan, and Spanish filmmaker Pedro Almodóvar, according to Variety.

Mossack Fonseca says it has operated for 40 years without any wrongdoing and released a statement saying, "Your allegations that we provide structures supposedly designed to hide the identity of the real owners, are completely unsupported and false. We do not provide beneficiary services to deceive banks," according to the BBC.

Some are now calling for these leaders — such as Icelandic Prime Minister Sigmundur Gunnlaugsson, who was revealed to have millions of dollars in an offshore account — to resign.