Former finance minister Khayam Turki, Attayar party co-founder Ghazi Chaouachi and protest leader Jawher Ben Mbarek were all detained as part of a crackdown on leading critics of Saied that has drawn a rebuke from rights organizations.
Islam Hamza, a lawyer for the three men, said they had all begun a hunger strike. Chaouachi's son Youssef told Reuters authorities had told him they were moving him to a different section of the prison and threatened to use violence to do so.
Dalia Ben Mbarek, a rights lawyer and the sister of Jawher Ben Mbarek, said the detainees had been transferred to cells with broken windows and a smell of sewage.
The police, interior ministry and justice ministry have declined to comment on the arrests. The prison system spokesperson did not respond to calls for comment on conditions in prison.
Most major political parties accuse Saied of a coup for shutting down the parliament in 2021 and moving to rule by decree before rewriting the constitution which he passed in a referendum last year with low turnout.
Saied says his actions were legal and necessary to save Tunisia from years of crisis at the hands of a corrupt, self-serving elite.
He has said those detained are criminals, traitors and terrorists and that any judge who frees them should be considered their accomplice.
