On 20 October 2017, an anonymous Reddit user hinted at the existence of the Paradise Papers. Later that month, the International Consortium of Investigative Journalists (ICIJ) approached the offshore law firm Appleby with allegations of wrongdoing. Appleby said that some of its data had been stolen in a cyberattack the previous year, and denied the ICIJ's allegations. After media outlets started reporting on the documents, the company said that there was "no evidence of wrongdoing", that they "are a law firm which advises clients on legitimate and lawful ways to conduct their business", and that they "do not tolerate illegal behaviour".
Appleby stated the firm "was not the subject of a leak but of a serious criminal act" and that "this was an illegal computer hack". "Our systems were accessed by an intruder who deployed the tactics of a professional hacker", the company said.
The documents were acquired by the German newspaper Süddeutsche Zeitung, which had also obtained the Panama Papers in 2016. According to the BBC, the name "Paradise Papers" reflects "the idyllic profiles of many of the offshore jurisdictions whose workings are unveiled", so-called tax havens, or "tax paradises".
The data breach comprises some 13.4 million documents—totaling about 1.4 terabytes—from two offshore service providers, Appleby and Asiaciti Trust, and from the company registers of 19 tax havens. Süddeutsche Zeitung journalists contacted the ICIJ, which has been investigating the documents with 100 media partners. The consortium made the data available to these media partners using Neo4j, a graph-database platform made for connected data, and Linkurious, graph-visualization software. This allowed journalists across the globe to undertake collaborative investigative work. The documents were released by the consortium on 5 November 2017.