Preacher Anjem Choudary holding a rally for Muslims outside Regents Park mosque in London on April 3, 2015, (Andy Rain/EPA-EFE)

LONDON — Islamist preacher Anjem Choudary was released from prison Friday, prompting concerns that his new freedom could spark extremist activity.

Described by Britain’s prison minister as “genuinely dangerous,” Choudary, 51, was jailed in 2016 for encouraging support for the Islamic State. He was automatically eligible for release after serving half of his prison sentence and will be subject to a number of restrictions during the remainder of his sentence.

According to the BBC, he will spend the first six months at a probation hostel in London and will have “up to 25” control measures in place, including restrictions on his Internet and phone usage, as well as limits on whom he meets and which mosques he goes to.

He won’t be able to travel outside of London without permission, and he will have to wear a GPS-enabled electronic tag. If he breaches any of his conditions, he could be recalled to prison.

Not one to shy away from the media, Choudary emerged from his bail hostel briefly on Friday to wave and smile at the throng of journalists outside. But in keeping with his control measures, he didn’t talk to the press.

Rory Stewart, Britain’s prison minister, told the Evening Standard last month that Choudary was “somebody who is a genuinely dangerous person . . . we will be watching him very, very carefully.”

But even with restrictions in place, some argue that his release could spur renewed support for Islamist extremists as well as energize anti-Islam activists like Tommy Robinson, for whom Choudary has long been a target.

“This is what the Tommy Robinsons of the world need — they need that sense of anger,” said Nick Ryan, a spokesman for Hope Not Hate, an anti-fascist research group. Ryan described the relationship between supporters of Choudary and Robinson as one that was “mutually beneficial.”

Robinson — whose real name is Stephen Lennon — is the founder of the far-right English Defense League and was recently released from prison on bail. He faces a hearing next week that could see him return to prison for contempt of court.

For more than two decades, Choudary led groups that, experts say, inspired supporters to commit acts of violence abroad and at home — people like Khuram Butt, one of the men behind last year’s terrorist attack at London Bridge that killed eight people.

“No other British citizen has had so much influence over so many terrorists,” Hope Not Hate wrote in a report titled “The Return of the Terrorist Ringmaster.” According to the group, Choudary has been linked to at least 123 Islamist terrorists.

Others have argued it’s important not to overstate his influence.

"At the end of the day, he is a pathetic groomer of others,” Mark Rowley, the former head of counterterrorism policing, told the BBC on Friday. “He is not some sort of evil genius we all need to be afraid of.”

For his part, Choudary has always denied that he is responsible for acts of violence. Indeed, for years the trained lawyer seemed particularly savvy at staying just on the right side of the law.

But in 2016, he was sentenced alongside co-defendant Mohammed Rahman to five-and-a-half years in prison. Rahman is expected to be released next week. Other supporters of Choudary’s have also been released recently.

“With their figurehead once more walking the streets, well founded fears that the group could once more reassemble are emerging,” said the Henry Jackson Society, in a briefing note on his release.

Earlier this week, the United Nations placed Choudary on a sanctions list, meaning he is subject to an asset freeze and travel ban.