A right-wing British activist, Tommy Robinson, walked out of a U.K. prison on parole more than a month early on Tuesday. A court granted Mr. Robinson’s release after he agreed to comply with an order he previously ignored.

Mr. Robinson, whose real name is Stephen Yaxley-Lennon, had been held since October for violating a court order barring him from repeating false allegations deemed libelous against a teenage Syrian refugee.

The boy was assaulted at a school and a video of the incident went viral. Mr. Robinson falsely claimed in a Facebook post that the boy attacked girls at the school. The boy’s family won a lawsuit against Mr. Robinson and he was ordered not to repeat the claims.

Despite the order, Mr. Robinson made a documentary called “Silenced” about his claims and pinned the film to his X profile. X’s owner, Elon Musk, expressed support for Mr. Robinson and shared his documentary.

Mr. Robinson went live on X moments after his release and thanked Mr. Musk for his support. “I have to say thank you to Elon Musk because without X, if we did not have X, everyone would just think that I lied. No one would have gotten any other narrative,” he said.

The “Silenced” documentary has had more than 100 million views. “These attempts at censorship — to silence, to cancel people — it hasn’t worked,” Mr. Robinson said. “You attempted to lock up the truth and that truth has been echoed around the world.”

Mr. Robison, who grew a bushy beard and long hair while incarcerated, said he was doing great despite “relentless attacks from the British state using lawfare as a weapon to silence me.” He announced that he would put together a free-speech festival in London later this year.

Mr. Robinson’s legal problems are not over. He is due in court next month on accusations that he harassed two journalists, the BBC reports. He also faces another trial related to his allegedly not allowing police access to his phone during a stop.

Claiming there is no free speech in Britain, Mr. Robinson said, “I faced relentless attacks from the British state using lawfare as a weapon to silence me.”

Lawyers for Mr. Robinson told the U.K. high court this month that he showed a “commitment” to comply with the order to stop spreading libelous content about the Syrian refugee. Part of that means that Mr. Robinson is required to stop distributing the documentary.