An undercover officer smashed a terror cell drumming up support for Islamic State extremists after he spent nearly two years infiltrating meetings to record their inflammatory speeches.
The officer identified only as Kamal forged close relationships with the Luton chapter of a banned group linked to hate preacher Anjem Choudary as he collected evidence, a court heard.
Equipped with a false identity including a fake name, fake wife and fake business, he spent 20 months recording hundreds of encounters, and meetings where scores of people heard speeches praising Islamic State in Iraq and Levant (Isil).
In one rant, one of the gang spoke of 40 truck bombs “driving down Oxford Street”, the Old Bailey was told.
Speeches were delivered to up to 100 people, including young children, and the group praised Isil and urged others to travel to Syria to fight.
Zaiur Rahman, 39, was convicted of arranging meetings after putting up a marquee in his back garden to host the Luton chapter of Al-Muhajiroun. Meetings were also held in a nearby Methodist church hall.
Mohammed Choudry, 23, was found guilty of encouraging support for Isil, while Mohammed Istiak Alamgir, 37, Rajib Khan, 38, and Yousaf Bashir, 36, were convicted of similar offences last summer.
The invitation-only gatherings in June and July 2015 featured speeches calling for gay people to be thrown from buildings, the court heard.
One was held on the anniversary of the London Tube bombings while in another Choudry spoke of “40 trucks driving down Oxford Street full of explosives”.
Choudry, who is married with a young child, told his audience: “My brothers, there is a wave coming. Either you be part of it or you drown. Either you like it or you don’t like it.’
Anjem Choudary, who was last year jailed for five-and-a-half years, spoke at one of the meetings in Rahman’s garden.
Those attending the speeches included Shazib and Junead Khan. Junead Khan is serving a life sentence for plotting to kill a US soldier in the UK, while Shazib Khan is serving a 13-year jail term for plans to fight alongside Isis in Syria.
Rahman, from Luton, was convicted of three counts of arranging meetings in support of a proscribed organisation, while Choudry, from Maidenhead, Berkshire, was convicted of one count of encouraging support for a proscribed organisation.
Judge Michael Topolski QC told the pair they had been convicted “of arranging meetings and speaking at a meeting in support of a vicious terrorist organisation, who’s members and supporters, just like you two, have hijacked and corrupted the principles and practices of an ancient and revered religion for its own purposes”.
Kamal accompanied Rahman and Choudry to a meeting where the speaker praised the massacre of 12 journalists at French satirical magazine Charlie Hebdo.
The court heard a secret recording where the speaker says: “It’s a great day, it’s excellent news.”
Alamgir also collected money at the talks to pay the legal fees of convicted terrorist Omar Bakri Muhammed – Anjem Choudary’s mentor, seen by many as the head of Al-Muhajiroun.
Speaking after the verdict, Commander Dean Haydon, head of Scotland Yard’s counter terrorism command, said: “These men were closely associated with Al-Muhajiroun, a dangerous group which has inspired and influenced numerous terrorists.
“Speeches like theirs inspire the terrorists of tomorrow and I am immensely pleased with the excellent work of my officers and Bedfordshire Police.”
All five men will be sentenced at a later date.