●What did MI5 and the police know about Mohammad Siddique Khan, the ring-leader of the 2005 London bombings, before the attacks took place?

Mohammad Siddique Khan had been arrested by West Yorkshire police as far back as 1993 for assault, though the first significant lead that could have shown his involvement in terror planning related to a 2001 training camp organised by two extremists. Some 40 men attended, but only nine were immediately identified by intelligence sources. It was only after 7/7 that Khan was identified as one of the other participants.