Four suspects were placed in pretrial detention for 30 days following their arrest late on Thursday, said Ramona Bolla, a spokeswoman for Romania's anti-organised crime and terrorism directorate (Diicot).
They are former professional kickboxer Tate, who is a British-US citizen, his brother Tristan and two Romanian citizens.
Tate and his brother were initially detained for 24 hours, but prosecutors had asked a Bucharest court to extend the detention of all four suspects as part of their ongoing investigation.
Since early 2021, the prosecution has been investigating the suspects and had already searched Tate's villa in April.
The four suspects allegedly recruited and exploited women by coercing them into “forced labour … and pornographic acts with a view to producing and disseminating such material” online to “obtain substantial financial benefits”.
Six potential victims have so far been identified.
Romanian police raided five locations across the country as part of their investigation.
Andrew Tate arrested in Romania over human trafficking case — video
Viral Twitter exchanges between Tate and Ms Thunberg this week on subjects ranging from cars with “enormous emissions” to pizza boxes fuelled speculation on social media.
Some internet users argued that the brand of pizza featured in a video posted by Tate in his angry exchanges with Ms Thunberg had helped police confirm his presence in Romania.
“This is what happens when you don't recycle your pizza boxes,” Ms Thunberg quipped on Twitter following Tate's arrest.
But Diicot spokeswoman Ms Bolla told AFP earlier on Friday that “it's not related”.
“To determine whether a person is in the country or not, we use a whole range of means,” she said, stressing that “arrest warrants and searches” had already been in place.
Ms Thunberg's representative confirmed to AFP that her tweet this morning — which has so far garnered about 2.4 million likes — was in fact a “joke”.
The Romanian authorities “have not been in touch with her”, the representative added.
Tate appeared on the Big Brother television show in 2016, but was removed after a video emerged showing him attacking a woman.
He moved to Romania several years ago with his brother.
Tate has been banned from many social media platforms for misogynistic remarks and hate speech, but was allowed back on Twitter after Elon Musk bought the company.
Who is Andrew Tate?
A former kick-boxing world champion, 36-year-old Tate has amassed millions of followers across Facebook, Instagram, Twitter, YouTube and TikTok.
He claimed in an interview with Piers Morgan this month that he was the “most googled man on earth”, but Google Trends ranked him the eighth most searched person globally in 2022.
His commentary across social media platforms has been met with controversy.
In 2017, he was banned on Twitter for saying that women should “bear responsibility” for being sexually assaulted.
Tate said last year on the Anything Goes with James English podcast: “I will state right now that I am absolutely sexist and I’m absolutely a misogynist.”
But he was reinstated to Twitter last month and has 3.7 million followers.
On his website, Tate has described himself as a multimillionaire who grew up “broke as a joke” with his brother in a single-mother household.
He was born to chess grandmaster father Emory Tate and mother Eileen Tate, who he described in an interview with The Times in September as “largely [a] housewife”.
He told the newspaper that his parents were together but that his father was in the air force and absent for long periods of time.
Of his father, he said: “He’d come home and say, ‘Look, your mother has to do the day-to-day stuff. I’m a man. I have to make sure you’re protected’.”
Tate first lived in Chicago, Illinois, but moved to a council estate in Luton in Bedfordshire as a child. His mother still lives in Luton.
He told The Times that he had children but declined to say how many.
“I am certain I will have more children than 99.9 per cent of the population of the western world. Double-digit children. And they all adore me. They see me as their hero and the women who have my children see me as a hero. Everybody close to me respects me,” he said.
There are 41 “tenets” on Mr Tate’s website, the first of which is: “I believe that men have the divine imperative to become as capable, powerful and competent as possible in this life.”
According to his site, Tate has led what is described as a “global community”, called The Real World, in which members are said to be educated and mentored to acquire wealth.
Its online description claims it is designed to “break people free from the Matrix”.
He often defends masculinity, insisting that masculine men have a “duty” to provide for and protect those they cared about.
“We have a duty to do things we don’t feel like doing because we know we’re supposed to do them and that’s why we stayed on the Titanic and died,” he told Morgan.” Those were masculine men.”
The influencer added that “overly emotional men are dangerous” and that teaching a man to act on their feelings produces school shooters and rapists.
Proclaiming himself “monumentally influential”, he told Morgan that he grew up with these views and got them from his family.