A man with a deep suntan and wearing a flowery shirt walked into the Cartier store in Cannes and threatened staff with a gun.
Two accomplices wearing crash helmets then entered the store, which is near the Carlton hotel popular with Hollywood stars during the Cannes film festival.
They took jewels from glass display cases before fleeing along Cannes' famous Croisette promenade on scooters after the raid on Monday.
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