It was the latest in a series of moves against imams, or prayer leaders, in France suspected of radical preachings or running counter to French values.
French intelligence suspects Mr Ali, who is married with four children, of being a leading figure among imams of the Salafist movement which holds to a strict interpretation of Islam.
Authorities want to expel him. While his expulsion order is under review, he was meant to have moved from the Paris area to live under house arrest in the rural Lozere region of south-central France. But he failed to do so and so was jailed last night.
France has expelled at least two imams in recent weeks, calling them a public danger.
With an estimated five million Muslims in France, the largest such population in Western Europe, French authorities want imams trained to preach an “Islam of France,” whose sermons reflect French values. The majority of imams in France are trained abroad and many do not speak French.
