Leak by Islamic State defector ‘goldmine’ for spy agencies

A disillusioned former member of Islamic State has passed a stolen memory stick of documents identifying 22,000 supporters in over 50 countries to a British journalist, a leak that could help the West target Islamist fighters planning attacks.

Leaks of such detailed information about Islamic State are rare and give Britain’s spies a potential trove of data that could help unmask militants who have threatened more attacks like those that killed 130 people in Paris last November.

A man calling himself Abu Hamed, a former member of Islamic State who became disillusioned with its leaders, passed the files to Sky News on a memory stick he said he had stolen from the head of the group’s internal security force.