Threats against 'Nazi salute' comic
Dieudonne M'Bala M'Bala, who performs as Dieudonne, claimed he received four phone calls on Tuesday threatening him and the Theatre de la Main d'Or, where he often appears, prosecutors said.
The comedian, who has a small but faithful following, is being investigated for an alleged anti-Semitic slur during a recent show directed at a journalist for France-Inter radio.
He is increasingly known for a hand gesture picked up by fans and celebrities described by detractors as an "inverted Nazi salute".
Most recently, West Bromwich Albion striker Anelka used the sign - one hand down, the other placed on the opposite shoulder - to celebrate a goal in a Premier League match. Both Anelka and Dieudonne claim the salute is anti-establishment and not anti-Semitic.
Interior minister Manuel Valls is seeking to ban Dieudonne's performances as a risk to public order.
Dieudonne has been convicted of inciting racism more than half a dozen times, most recently last year for a song using a play on words making light of the Holocaust. Dieudonne denies that is the case but lost an appeal in November.
Dieudonne embarks on a tour of France this month, but some cities have said they do not want him in town.
Mayor of Nancy Andre Rossinot said that when free expression "transforms into racist, xenophobic and anti-Semitic propaganda there is reason to react".