Andrew Tate and his brother Tristan according to his representative have been detained in Romania after European arrest warrants were issued by the UK.
The allegations, including sexual aggression, cover 2012 to 2015, his team said.
The Tate brothers “categorically reject all charges”, the statement said.
Romanian police said European arrest warrants for two men were issued by UK authorities for sexual offences on Monday.
The alleged offences also included exploiting people in Great Britain, the Romanian police statement said.
The two men were presented to the prosecutor attached to the Bucharest Court of Appeal, who ordered their detention for 24 hours, police said.
A representative for the controversial influencer said the court will make a decision on Tuesday as to whether to “execute the mandate”.
They described the arrest warrant as a “bewildering revival of decade-old accusations” leaving the brothers “dismayed and deeply troubled”.
In December, Andrew Tate, 37, and his brother Tristan, 35, who are dual UK-US nationals, were ordered by a Romanian court not to leave Romania after the brothers made a request to visit their mother in hospital in the UK.
The brothers are being investigated by Romanian authorities over separate allegations of rape, human trafficking and forming a criminal gang – charges they deny.
They are accused of exploiting women via an adult content business, which prosecutors allege operated as a criminal group.
Two female Romanian associates were also named alongside the brothers in an indictment published in June, and seven alleged victims were identified.
Mr Tate has repeatedly claimed Romanian prosecutors have no evidence against him and there is a conspiracy to silence him.
Andrew Tate is a self-described misogynist and was previously banned from social media platforms for expressing misogynistic views.
