Mauritania's state news agency says Moammar Gadhafi's ex-spy chief, Abdullah al-Senussi, has been handed over to Libya, where he is expected to stand trial.
Al-Senussi was arrested in March after sneaking into Mauritania using a disguise and a fake passport. Since then, Libyan authorities have called for the extradition of the former intelligence chief, who is also wanted by the International Criminal Court.
Mauritania had insisted on trying al-Senussi on charges of illegally entering the country. But government officials confirmed that he left the country Wednesday on a Libya-bound flight.
The ICC issued an arrest warrant for al-Senussi in June, saying he was responsible as an "indirect perpetrator" on two counts of crimes against humanity, including murder and political persecution.
France had also wanted al-Senussi extradited there to serve a life sentence handed down in absentia for his role in the 1989 bombing of a French commercial airliner that killed 170 people.
Al-Senussi is the brother-in-law of ex-Libyan leader Gadhafi, who was forced from power by a revolt that in October 2011 led to his death and the arrest of several of his key allies.