On April 3, 2016, Süddeutsche Zeitung and the International Consortium of Investigative Journalists (ICIJ) began publishing 11.5 million leaked files—about 2.6 terabytes—taken from Panamanian law firm and corporate-services provider Mossack Fonseca. The records covered more than 214,488 offshore entities, with documents dating to the 1970s. Offshore companies can be legal, but the reporting identified structures apparently used for fraud, tax evasion, kleptocracy, and sanctions evasion. The leak also exposed conflicts of interest, including Icelandic Prime Minister Sigmundur Davíð Gunnlaugsson’s undisclosed stake in Wintris Inc., a creditor of Icelandic banks; he resigned in 2016.
The investigation relied on encrypted communications with the anonymous whistleblower “John Doe” and collaboration among roughly 100 media organizations in 25 languages. Reporters used OCR, Apache Solr, Apache Tika, Neo4j, Linkurious, and other tools to search and map the data, later publishing a database covering more than 200,000 entities. ICIJ and European newspapers reported in April 2019 that litigation, fines, and back taxes had recovered more than $1.2 billion, including $253 million in the United Kingdom and $237 million in Denmark. German prosecutors issued an international arrest warrant for founders Jürgen Mossack and Ramón Fonseca in October 2020, while a Panamanian judge acquitted all former Mossack Fonseca employees in June 2024, citing insufficient evidence and chain-of-custody problems.