American counter-terrorism chiefs are demanding a full explanation from Britain of how radical cleric Abu Hamza was able to smuggle murderous messages from his UK prison cell to Al Qaeda's deputy leader.
The major diplomatic row comes in the wake of a long-running battle by US prosecutors to extradite the former imam of London's Finsbury Park mosque to stand trial in America.
Hook-handed Hamza was jailed for seven years in Britain in 2006 for inciting murder and racial hatred and is held at Belmarsh prison, South-East London, supposedly one of Britain's most secure jails.
But according to senior American intelligence sources, Hamza evaded the extensive security measures surrounding him to send a series of questions to Ayman al-Zawahiri, Osama Bin Laden's right-hand man. - Mail Online