Tunisia's interior ministry on Thursday denied that former prime minister Hamadi Jebali had been arrested, contradicting a report from his old party and a notice on his official Facebook page.
The moderate Islamist Ennahda party said Jebali had been detained, demanded his release and accused the authorities of cracking down on dissent.
The statement on the 73-year-old's Facebook page also said he had been arrested, without saying when or going into further details.
The interior ministry said Jebali had not been arrested. It issued a statement saying prosecutors had launched an investigation into a factory on land owned by Jebali's wife, and that he had insisted on accompanying her to the police station.
Jebali himself did not immediately respond to phone calls seeking comment.
Ennahda was the biggest party in Tunisia's parliament before President Kais Saied dissolved the assembly and seized executive powers last year.
The party and other critics called the president's move a coup. Saied said the move was temporary and needed to save Tunisia from he saw as a corrupt, self-serving elite.
