Andrew Tate, a controversial online influencer, is said to have been jailed in Romania as part of a human trafficking and rape investigation.
Mr. Tate’s house in Bucharest, where he was held alongside his brother Tristan, was raided.
According to Reuters, a lawyer for the boys confirmed their imprisonment.
The former kickboxer rose to prominence in 2016 after being booted from the British TV show Big Brother due to a video that purported to show him assaulting a woman.
He went on to become well-known online, with Twitter banning him for claiming that women should “carry responsibility” for sexual assault. He was later reinstated.
The brothers, along with two Romanian nationals, have been under investigation since April.
Mr. Tate and his brother appear to be led away from a beautiful villa in a video extensively distributed on social media.
The Directorate for Investigating Organized Crime and Terrorism (DIICOT) of Romania published a statement in which it stated that two British citizens and two Romanian citizens were accused of being part of a criminal cell focused on human trafficking.
It also published video footage of the raid, which showed guns, knives, and money on display in one area.
Five years ago, Mr. Tate relocated to Romania.
Mr. Tate, a British citizen born in the United States, formerly competed professionally as a kickboxer and won world titles.
He entered the Big Brother house in 2016 but was quickly evicted after a video surfaced showing him beating a woman with a belt.
At the time of his dismissal from the program, Mr. Tate stated the footage had been manipulated, calling it “a pure falsehood attempting to make me seem terrible”.
He went on to become well-known online, with Twitter banning him for claiming that women should “carry responsibility” for sexual assault.
Mr. Tate has been removed from other social media platforms like YouTube, Facebook, and Instagram, with TikTok, also banning him, claiming “misogyny is a vile ideology that is not permitted”.
His articles on other online sites advocate bigotry and attack women and have millions of views, with the BBC’s disinformation and social media correspondent Marianna Spring noting earlier this year that his work had “raised worries about the real-world effect it could have”.
Following Elon Musk’s takeover of Twitter, he, along with former US President Donald Trump, was recently let back on.
Mr. Tate was embroiled in a Twitter spat with climate campaigner Greta Thunberg on Wednesday.