Shakil Chapra, 43, who also goes by the alias Abu Haleema, has links with London Bridge attacker Khuram Butt and, Kingston Crown Court heard, joined the banned al-Muhajiroun (ALM) group, led by notorious extremist Anjem Choudary, 54, in 2013.
“You are to be sentenced for a single count of distributing a terrorist publication - posting a video agreed to give indirect glorification to and thus encouragement of terrorism,” the judged told Chapra, who pleaded guilty to disseminating a terrorist publication in March.
On Friday, Judge Peter Lodder QC sentenced Chapra, from Slough, to two-and-half years in jail, with an extra 12 months on extended licence, Press Association has reported.
“From at least 2013, when you joined ALM, you have held extreme Islamic views,” the judge added.
Last November. Chapra was arrested for his link to Shehroz Iqbal, 29, who was jailed for eight-and-a-half years at the Old Bailey last year, having been found guilty of encouraging terrorism.
The court found messages from Chapra on a 22-strong WhatsApp group for extremists, named From Dark to Light, on Iqbals phone.
The court heard Iqbal made a video inciting a terror attack on London’s Royal Festival Hall and posted it to an extremist WhatsApp group with the words: “Attack, attack.”
The WhatsApp chat thread contained postings by Chapra including a video on September 11 2019 - 18 years after the terrorist attacks in the US.
The one minute and 33 second clip features the leader of Boko Haram - which was banned as a terrorist group in the UK in 2013 - Abu Bakr Shekau, who ends his speech about kidnapping school children by firing a machine gun into the air before throwing the weapon to the ground.
Chapra wrote: “I will show you the most gangster Nigerian” and following the video posted a 100% and three flame emojis, which prosecutors said was an endorsement of the terrorist’s message.
The court heard other messages from some of the group’s members, included “happy 9/11” and “sweet 18 party”, while Chapra boasted of his links to Choudary, having “studied with Anjem back in the day”.
Following his arrest, Chapra, who also posted his own extreme videos to 232 members of a channel on encrypted messaging app Telegram, said: “I used to buy into Isis but not anymore... You say September last year, I don’t support 9/11.”
But prosecutor Alistair Richardson said he “remains a committed and highly concerning extremist”.
“The defendant holds and continues to hold extreme Islamic views, he has held those views for some years,” he said.
Hossein Zahir, defending, said Chapra’s “ideological position has changed” and there has been “a shift in his view” after breaking ties with former associates.
“My client is no longer in the category that supports Isis,” he said. “There has been a falling out of some magnitude some time ago.”
Chapra has links to London Bridge attacker Khuram Butt, 27, who he appeared alongside in Channel 4 documentary The Jihadis Next Door in 2016, praying in front of the black flag associated with Isis in London’s Regent’s Park.
Butt, along with Rachid Redouane, 30, and Youssef Zaghba, 22, killed eight people and injured dozens more when they ploughed a van into pedestrians on London Bridge and then began stabbing people around Borough Market on June 3 2017.
Additional reporting by Press Association