Former professional kickboxer and controversial online personality Andrew Tate has been detained in Romania for alleged human trafficking, rape and setting up an organized criminal group, prosecutors said.

British citizen Tate and his brother Tristan were expected to appear in court in Bucharest on Friday, with a proposal to keep them in pre-trial detention for 30 days.

"At the beginning of 2021, (the) four suspects formed an organized criminal group with a view to committing the crime of human trafficking on the territory of Romania, but also other countries," said prosecutors from Romania's organized crime and terrorism investigations directorate (DIICOT) in a statement dated Thursday.

The brothers, and two Romanians also detained, allegedly trafficked, recruited and exploited women by coercing them into "pornographic acts with a view to producing and disseminating such material" online.

So far six victims have been identified who have been sexually exploited by the suspects.

Several locations were raided across Romania as part of the investigation launched in April.

Andrew Tate appeared on the Big Brother television show in 2016, but was removed after a video emerged showing him attacking a woman.

Tate, who moved to Romania several years ago with Tristan, has been banned from many social media platforms for misogynistic remarks, but was allowed back on Twitter after Elon Musk bought the company.

On Wednesday, Tate got into an argument with Swedish climate activist Greta Thunberg on Twitter after he tweeted that he owned cars which were producing "enormous emissions".