Turkish authorities have detained a suspected close associate of the notorious Islamic State (IS) group militant known as “Jihadi John” who Washington believes was likely killed in a drone strike in Syria, a Turkish official has said. The official told AFP that Aine Lesley Davis, like “Jihadi John” a British citizen who guarded foreign prisoners in Syria, was believed to be among several Islamist suspects detained in a swoop in Istanbul and was now being held by the Turkish authorities. Turkey was “99 per cent certain” that the man detained was Davis, the official said, adding that this had already “been confirmed by the initial data”. The official described Davis as the “closest associate” of “Jihadi John”.Davis, a London-born British Muslim who turned to Islamist militancy, described by British media in the past as a key figure in the IS network.