Notorious Islamist preacher Anjem Choudary must complete what is being described as "Britain's first compulsory deradicalization" program as part of his probation following his early release from prison, The Times of London reported late Sunday.

Choudary, 51, served less than half of a five-and-a-half-year prison sentence for encouraging support for the Islamic State terror group. He was released from the high-security Belmarsh prison in southeast London on Oct. 19 but will be subject to strict supervision.

As part of the course, The Times reports, Choudary is required to receive "mentoring and theological 'advice.'" If he does not attend the sessions, the paper reports that he will be returned to prison to serve out the remainder of his sentence. The onetime solicitor from east London is also expected to wear an electronic tag, face a nighttime curfew and be barred from contacting anyone who has been charged with extremist-related offenses unless he receives prior approval from authorities. His name has also been added to a United Nations sanctions list, which means the U.K. government could freeze his assets and bar him from traveling.

According to The Times, approximately 100 people passed through the so-called "desistance and disengagement programme" (DDP) last year as part of a trial period. The paper reports 230 extremists -- including one-time ISIS fighters returning to the U.K. from Syria -- are expected to take part in the program by June. Some returning fighters who cannot be prosecuted due to lack of evidence must take part in the program to be allowed back into the country.

FILE - This is a Friday, April 3, 2015 file photo of Anjem Choudary, a British Muslim social and political activist and spokesman for Islamist group, Islam4UK, speaks following prayers at the Central London Mosque in Regent's Park, London. Anjem Choudary, a radical preacher convicted of inviting support for the Islamic State group, has been released from Belmarsh prison in southeast London on Friday Oct. 19, 2018. (AP Photo/Tim Ireland, File)

Choudary has been one of the most high-profile faces of radical Islam in Britain for years, leading groups under names including al-Muhajiroun, Islam4UK and Muslims Against Crusades.

Several people who attended Choudary's rallies and events have been convicted of violent attacks, including the two Al Qaeda-inspired killers who ran over British soldier Lee Rigby and stabbed him to death in 2013.

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Until he was charged under the Terrorism Act, the firebrand preacher gained attention for headline-grabbing activities that provoked outrage but were protected by the law. They included protesting outside the U.S. Embassy on the anniversary of the Sept. 11 attacks and burning memorial poppies on Britain's annual Remembrance Day honoring slain service members.

However, he ran into trouble in 2014 after his name appeared on an oath circulating online that declared the legitimacy of the "proclaimed Islamic Caliphate State." Choudary said the oath was made without his knowledge.

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Choudary was convicted in 2016 and qualified for early release because of time served before his conviction.

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The Associated Press contributed to this report.