The group was founded in 1996 by north London-based Syrian-born cleric Omar Bakri Muhammad to establish an Islamic caliphate in the UK.
Its members have been implicated in many extremist attacks, including the murder of British soldier Lee Rigby in 2013, and attacks on London Bridge in 2017 and 2019.
Despite claims it had been disbanded, prosecutors said Al-Muhajiroun continues to exist under different names, including the New York-based Islamic Thinkers Society.
US law enforcement officers infiltrated the group and attended online lectures it hosted with Choudary in 2022 and 2023, sparking police probes in Britain and also Canada.
“There are individuals that have conducted terrorist attacks or traveled for terrorist purposes as a result of Anjem Choudary’s radicalising impact upon them,” Dominic Murphy, of the Metropolitan Police, said after his conviction.
“ALM’s tentacles have spread across the world and have had a massive impact on public safety and security,” added Murphy, who heads the force’s counter-terrorism command.
Rebecca Weiner, the deputy commissioner of the New York Police Department, told reporters Choudary’s conviction was “historic” and described him as a “shameless, prolific radicaliser”.
“It is usually the foot soldiers, the individuals who are brought into the network who go on to commit the attacks who are brought to justice,” she said.
“It’s rarely the leader, which is what makes this a particularly important moment.”
The prosecution told the court that Choudary, 57, from Ilford in east London, took over as head of Al-Muhajiroun while Muhammad was in prison in Lebanon from 2014 to 2023.
Choudary, a former lawyer, was jailed for five and a half years in 2016 for encouraging support for the Daesh terrorist group and was released early from prison in 2018.
At his trial, he denied inviting support for ALM during the online lectures and claimed the group had been disbanded.
But prosecutors said the police investigations showed that ITS was “the same” as ALM, while Murphy said it was “clear” that Choudary had an influence online.
Choudary’s co-defendant Khaled Hussein, 29, from Edmonton, Canada, was also convicted of membership of ALM.
Hussein said to have been “a follower and dedicated support” of Choudary, was arrested at London Heathrow Airport after arriving on a flight on July 17.
Both men will be sentenced on July 30.
