The ousted leader of the Comoros island of Anjouan, Mohamed Bacar, was held in custody Friday on the French island of Reunion because of an extradition request by Comoran authorities, prosecutors said.
"This detention follows a request to the French government by the Comoros justice minister for (his) arrest with the aim of extradition," Reunion deputy prosecutor Jean-Robert Dobanton told journalists.
Comoran and African Union troops last week ousted Bacar, re-elected last June in a poll declared illegal by federal government and that was never recognised by the African Union.
There is no extradition agreement between France and the Comoros. An agreement was reached by diplomatic contacts.
The Comoran authorities now have a month to lodge an extradition request to be examined by the appeals court here, the prosecutor's office said.
A further 21 people accompanying Bacar were likewise in custody. A lawyer representing them described the arrests as scandalous.
"The accusations against my clients have not been given in detail and refer to no date, place or victim," said Marie Briot.
"The procedure usually applies to fugitives. But Mr. Bacar has been confined to a residence at an airbase on Reunion where he is kept under 24-hour watch."
The president of Anjouan's court of appeal, Lailizamane Abdou Cheik, was sworn in Monday as the island's leader, pending elections in two or three months.
The Union of the Comoros consists of three islands in an archipelago, each governed by their own leader and parliament, but merged into a federal union with an overall presidency after decades of instability.
Anjouan, the federation's second largest island and the only one equipped with a maritime cargo port, seceded completely from the three islands in 1997, before joining again in 2001.