An influential imam has lost a libel action against the BBC after a judge ruled he had promoted violence.
London-based Shakeel Begg sued after being accused on the Sunday Politics show of espousing extreme beliefs.
The judge said Lewisham Islamic Centre's chief imam had hidden his true views behind a cloak of respectability.
Mr Justice Haddon-Cave said he "clearly promotes and encourages violence in support of Islam and espouses a series of extremist Islamic positions".
"On occasions when it has suited him…he has shed the cloak of respectability and revealed the horns of extremism."
A spokesman for the BBC welcomed the ruling against the imam who now faces an enormous legal bill.
Imam Begg is extremely influential among followers of hardline conservative Islam in the UK.
He has been involved in inter-faith work with Jewish and Christian leaders but has also faced accusations of extremism, including supporting organisations that have campaigned on behalf of suspected terrorists.
He personally appealed to the self-styled Islamic State group to spare the British hostage Alan Henning - a sign of his theological credibility within their branch of Islam.
'Jekyll and Hyde'
In November 2013, BBC presenter Andrew Neil alleged on the Sunday Politics that the imam had said that jihad was the greatest of deeds.
Jihad typically refers to a personal struggle to do good - but violent extremists use it to refer to fighting holy war.
Despite the imam's protestations during the libel trial, Mr Justice Haddon-Cave said four of his speeches showed he had promoted such violence and two that he had espoused extremist positions.
"Shakeel Begg, is something of a Jekyll and Hyde character," he said.
"He appears to present one face to the general, local and inter-faith community and another to particular Muslim and other receptive audiences. The former face is benign, tolerant and ecumenical.
"The latter face is ideologically extreme and intolerant."
In one speech in 2006, Imam Begg encouraged a student audience to fight in the Palestinian territories. Two years later he praised Muslims who had travelled abroad to fight enemies of Islam.
A third speech outside the maximum security Belmarsh Prison in south-east London, which holds some of the most dangerous terrorism convicts in the country, was described by the judge as "particularly sinister".
He said: "The various core extremist messages which emerge from the claimant's speeches and utterances would, in my view, have been quite clear to the audiences.
"The claimant's ostensible cloak of respectability is likely to have made his [extremist] message in these speeches all the more compelling and seductive. For this reason, therefore, his messages would have been all the more effective and dangerous.
"It is all too easy for someone in the claimant's position of power and influence as an Imam to plant the seed of Islamic extremism in a young mind, which is then liable to be propagated on the internet."
A spokesman for the BBC said: "We were right to stand by the journalism of the Sunday Politics. The judge has concluded, based on the evidence, that Imam Begg has preached religious violence and an extremist worldview in his remarks."