Tommy Robinson was filmed being arrested after visiting Canada for a podcast tour.
Officers in Calgary handcuffed the right-wing activist, 41, on suspicion of an immigration offence and led him into the back of a police van.
Robinson, whose real name is Stephen Yaxley Lennon, said he was released later on Monday but had to hand in his passport to Canadian authorities.
He posted on X: “Ok I’m FREE, well sort of, none of this makes sense.
“I’m now detained in Calgary, prevented from leaving the city, these conditions stop me from continuing my tour of Canada and meeting with guests for podcasts. I’m not even allowed to leave to travel home.”
In a video posted to his X account, he asked what he is being detained for: “This is absolutely insane. Get me a lawyer? Can you not tell me what I’m under arrest for?”
Robinson visited the country for a podcast talk in front of 150 people, with an outlet called Rebel News, to talk about “freedom of speech” and “lawfare” and his battles with British police.
He was expected for more podcast appearances in Edmonton and Toronto on a “three-city tour”.
He told reporters outside the station: “I asked them ‘What if I just want to go home?’ and they said ‘You’re not allowed to’”.