The investigation was opened following information received from an elected official in the Paris region and also from public statements about the scandal that has engulfed VW, which has admitted 11 million vehicles worldwide are equipped with the software that dupes pollution emission testing.
Volkswagen officials admitted on Wednesday that there are close to 1 million vehicles in France that are equipped with pollution-cheating software.
They are mostly Volkswagen models, but also include Skoda and Seat cars which are part of the VW group.
The German government has given VW until October 7th to outline how it plans to resolve the crisis that has rocked carmakers around the world and wiped €29 billion ($33 billion), or 38 percent, off VW's market capitalisation over the past ten days.
The latest scandal broke when US officials publicly accused Volkswagen of cheating and launched a probe which has also seen a growing list of other countries launch investigations.
Volkswagen's CEO Martin Winterkorn resigned amid the emerging scandal, and he is under investigation in Germany.