The incident took place early on Tuesday morning in a rest area on the A31 between Dijon and Nancy in the east of the country. Xavier Baligant, a divorced father aged 29, was returning home from holiday with his two young children after a holiday in the south of France.
His body was found lying in front of the toilets in the lay-by. According to TV channel M6, he had been shot a total of five times, once in the head.
"The way he was killed suggests a contract killing," according to the channel's report which cited a source close to the inquiry.
Police are working with Belgian authorities to see whether Baligant was known to his assailant or whether he was the unlucky victim of being in the wrong place at the wrong time.
A report in local daily Est Republicain says that a CCTV camera at the scene could give police a clear view of what happened, depending on the quality of the footage.
The incident happened at 2am when it was dark. Other footage will be used to track Baligant's movements and to see whether any car was following the victim.
The man from Nivelles in Belgium, south of Brussels, where he worked for a pharmaceutical company. Family and friends in Belgium have spoken of a "lovely guy with no problems who took great care of his two children." Another said he was "a great guy and incredibly kind."