Rached Ghannouchi, Tunisia's former parliament speaker, appeared before an investigative judge on Tuesday to be questioned on suspicion of incitement against the police, which he and his Ennahda party deny.
Ghannouchi's lawyer said the accusation was based on a complaint by police about a speech he gave last year at the funeral of a party member, saying the deceased "did not fear a ruler or a tyrant, he only feared God".
The lawyer said the police objected to the reference to a tyrant and that they viewed the language as close to that used by extremist militants to describe secular authorities.
Ghannouchi, who was greeted outside the court by dozens of his supporters and activists, has described the case against him as "empty and fabricated, and a continuation of the political targeting of enemies of [President] Kais Saied".
The leader of Tunisia's main opposition coalition, the National Salvation Front, meanwhile denounced the "judicial relentlessness" targeting Ghannouchi.
"It is a short-sighted policy in the face of economic and social failures and the international isolation" of the authorities, Ahmed Nejib Chebbi told AFP outside the court.
"Repression has never stemmed the flow of freedom," he added.
Last year Ghannouchi was brought before judges to answer accusations of money laundering related to Ennahda financing and that the party had helped Tunisian extremists go to Syria to fight.
