One of the most vocal critics of the Central African Republic's government is being questioned by security officials following his arrest at the country's main airport.

Dominique Désiré Erenon leads the March for Democracy and the People's Salvation (MDSP) party and had been living in exile in France for the past three years.

He fiercely opposed 2016 constitutional reforms which extended presidential powers - a move many observers described as a step backward for democracy in the conflict-torn nation.

His arrest came after President Faustin-Archange Touadéra publicly called on all Central Africans in the diaspora to return home. Erenon responded to this call and was detained on arrival.

Central African authorities have not disclosed the reasons for his arrest on Friday or any formal charges. The silence has fuelled widespread speculation and criticism among civil society groups.

Opposition supporters see his arrest as part of a growing pattern of political intimidation, three months before elections are held in December.

After his interrogation by the Research and Investigation Section (SRI), reports say he is expected to be referred to the public prosecutor for a hearing.

Erenon's family say they are monitoring the situation closely and will decide on whether to hire legal representation, reports the French-language news site RFI.

Formerly a constitutional expert working for the African Union and lecturer in public law at the University of Bangui, Erenon fled to France in 2022 saying he had escaped an attempted abduction.

His party said he came home last week to resume his teaching duties and "participate freely in national political dialogue".

He returns at a time of tightening state control amid the ongoing presence of Russian-linked mercenaries supporting the government.