Tunisia's main journalism union said anti-terrorism police detained a radio reporter on Friday for refusing to reveal his sources on a story about militants, describing the decision as a new attempt to undermine press freedom.
Amira Mohamed, an official from the National Syndicate of Tunisian Journalists, said the reporter from Mosaique FM was held for questioning after broadcasting a story about authorities breaking up a militant cell.
The police's National Unit for Investigation of Terrorist Crimes did not immediately respond to phone calls seeking comment.
"What is happening is a shame, they used the anti-terror law to target the freedom of the press, and this is a very dangerous step," Amira Mohamed said.
Freedom of speech and press was a key gain for Tunisians after the 2011 revolution that ended the rule of former President Zine El Abidine Ben Ali and triggered the Arab spring protests.
However, the democratic system adopted after the uprising is in deep crisis after President Kais Saied last year suspended the parliament, seized executive power and brushed aside the constitution to rule by decree.
Saied has promised to uphold rights and freedoms won in the revolution, but his critics say his actions, which also include replacing a body that guaranteed judicial independence, show he is determined to cement one-man rule.
The journalists' union has also said freedom is seriously threatened and has warned that members in state media may go on strike because of what it called attempts by the presidency to control state television.
However, media including the state-owned TAP news agency have continued to broadcast items unfavourable to the president, including reports on protests against his moves and direct criticism of him by opponents.
(Reporting By Tarek Amara; Editing by Andrew Heavens, William Maclean)