The names, addresses and phone numbers of 22,000 Islamic State recruits have been leaked by a disillusioned member of the organization, Sky News reported Thursday.
Based on a 23-question form given to those applying to join Islamic State ranks, the documents contain personal details of jihadis from at least 51 countries and even the names of those who recruited and sponsored them.
Sky News obtained the files on a pen drive stolen from the head of Islamic State's internal security police, Abu Hamed - a former fighter for the Free Syrian Army who defected to join the extremist militia and then grew disillusioned with it.
On Monday, Germany's Federal Criminal Police (BKA) said it was in possession of a trove of Islamic State documents it believes to be authentic, but declined to comment on how it obtained the files, how many documents the trove comprises and how long it has had them.
The BKA failed to return a call on Thursday to confirm the documents are the same set leaked to Sky News.
Germany's Interior Minister Thomas de Maiziere on Tuesday confirmed the government's possession of the documents and said the information on foreign fighters, including those from Germany, would facilitate "speedier, clearer investigations and stricter prison sentences."
The revelation was originally reported by Germany's Sueddeutsche newspaper and public broadcasters WDR and NDR.