Ibrahim Aziz Ouattara, 25, was arrested on November 3 in central Mali on his way to join the Islamists, after allegedly entering Mali through Portugal under a false identity.

He faces potential terrorism charges in France.

Islamist rebels had seized control of northern Mali last year but were dislodged from their strongholds after a French-led intervention launched in mid-January.

About 4,000 French soldiers remain on the ground in Mali, working with Malian and West African troops to hunt down rebels who fled to the country's northern mountains.