BERLIN: Germany’s federal criminal police said on Thursday they are in possession of files containing personal data on members of the extremist Daesh group and believe them to be authentic.

The announcement came after Britain’s Sky News reported it had obtained 22,000 Daesh files on the border with Turkey and Syria, files that detail Daesh fighters’ real names, where they were from, telephone numbers, and even names of those who sponsored and recruited the militants.

Though the significance of these files is yet to be gauged, they could be the largest yet treasure trove of documents found on Daesh and the most significant leak on its past and present fighters and operations across the Mideast.

They could also shape the campaign against the extremist group, which emerged from Al-Qaeda in Iraq. The cache, exposing its members and their families, could undermine its future ability to recruit and inspire would-be members.

US Army Col. Steve Warren, spokesman for the US-led coalition against the Daesh, said the information could help the coalition fight the Daesh group by aiding in a crack-down on Daesh’s foreign fighter networks.

He said that while he was not able to verify the documents, he hoped that “if there is a media outlet that has these names and numbers, I hope they publish them.” This would help bring attention to the problem of foreign fighters joining Daesh, and would help law enforcement crack down on the problem, he said.

“This would allow the law enforcement apparatus across the world to become much more engaged and begin to help do what we can to stem this flow of foreign fighters, so we’re hopeful that its accurate and if so we certainly plan to do everything we can to help,” he said.

Sky said the files were passed on to them on a memory stick stolen from the head of Daesh’s internal security police by a former fighter who had grown disillusioned with the group.

Germany’s Sueddeutsche Zeitung newspaper reported it had also obtained “dozens” of similar files on the Turkey-Syria border, where it said Daesh files and videos were widely available from anti-Daesh Kurdish fighters and also members of the Daesh group itself.

A spokeswoman for Germany’s Bundeskriminalamt, speaking on condition of anonymity to discuss the matter with the media, said her agency is currently evaluating the files. She declined to say where the agency obtained the files, how many documents are involved and how long it has had them.