A Tunisian judge on Thursday issued an international warrant to summon former president Moncef Marzouki from Paris for questioning, state TV reported.
President Kais Saied in October ordered the Justice Ministry to open an inquiry into Mr Marzouki, 76, days after the former leader urged France not to support his “dictatorial regime”.
Mr Marzouki has emerged as a vocal critic of Mr Saied, who on July 25 sacked the government, suspended the legislature and seized control of the judiciary, later moving to rule by decree in the North African nation.
State television did not give any reasons for Thursday’s warrant, and the prosecution was not immediately available for comment.
He has used media appearances to accuse the president of carrying out a coup.
Mr Marzouki, Tunisian leader from 2011 to 2014, told anti-Saied demonstrators in Paris in October that Mr Saied had “plotted against the revolution and abolished the constitution”.
Days later, the president accused “traitors that seek refuge overseas” of threatening Tunisia’s sovereignty, ordered the enquiry against him and revoked his diplomatic passport.
“He is the greatest enemy of Tunisia,” Mr Saied said.
In a Facebook post, he slammed “a nascent dictatorship in which the dictator is confused with the nation, recalling the Ben Ali regime, under which opposing the dictator was considered treason”.
Mr Marzouki, who lived in exile in France for a decade during the rule of dictator Zine El Abidine Ben Ali, said he was “not concerned by any decision issued by these illegitimate authorities”.