Western intelligence services examined today a potential treasure trove of leaked IS registration documents, some of which were deemed likely to be authentic by the German intelligence service despite the doubts of many experts.
The information, which could help track down current and former Islamic State group jihadists, was included in forms which new recruits had to fill out, British and German media reported.
The documents contain details like names, dates of birth and phone numbers for people from 51 countries including from Britain, northern Europe, the Middle East, north Africa, the United States and Canada.
British broadcaster Sky News said it had shared with British security services documents with the identities of some 22,000 IS group members.
While Britain's interior ministry said it would not comment on national security matters in line with normal policy, a spokeswoman for Prime Minister David Cameron said the government would "look at how this information can be used in the fight against Daesh," another term for Islamic State.
"If it can, then we would welcome that," she said, adding that the government had not been aware of the story before it was reported by Sky.
German federal police spokesman Markus Koths said there was "a very high probability" that documents reported by German media as identifying German jihadists were genuine.
"We are therefore taking them into account as part of our law enforcement and security measures," he added.
Fredrik Milder, a spokesman for Sweden's Sapo intelligence service, meanwhile told TT news agency: "We are aware of the existence of this list."
"Our security services have received such information," he said.
