The runner-up in Tunisia's 2019 presidential election, Nabil Karoui, has been placed in pre-trial detention in neighbouring Algeria, accused of "entering the country illegally", local media reported Sunday.

Karoui and his brother Ghazi, an MP, had faced a hearing before a magistrate in the northeastern city of Constantine, the Ennahar newspaper wrote citing "judicial sources".

Constantine prosecutors could not immediately be reached for comment.

Karoui was arrested in late August by Algerian border police, with Tunisia releasing a warrant for his arrest the day after.

Algeria and Tunisia are bound by an agreement stipulating the extradition by either country "of any person prosecuted or convicted" in the other.

Any extradition request must be "accompanied by an official document from the authorities".

Karoui founded the private Tunisian channel Nessma TV, which is partly owned by Italy's former prime minister Silvio Berlusconi.

He has been under investigation since 2017 in a money laundering and tax evasion case.

He was arrested in 2019 and spent more than a month in prison at the height of the presidential election campaign.

He was freed but rearrested last December and spent six months in pre-trial detention before being let out again in June.

Karoui came second in the 2019 election to President Kais Saied, a retired law professor and political newcomer.

*This story was edited by Ahram Online.