Local government officials in the Burgundy region of central France said passengers aboard the train from Brussels and heading to the southern city of Marseille said passengers had raised the alarm over "a suspicious gas smell".
The TGV train was stopped and while one carriage went on to Marseille, another containing some 250 passengers was evacuated, said a spokesman for the SNCF rail operator.
Specialist firemen with the Nuclear, Biological and Chemical Risk (NRBC) unit were dispatched to search the train.
It was traced to a passenger's luggage containing several items of fermented food, notably a "very smelly package of meat", said the spokesman.
After two and a half hours passengers were allowed back on the train.
Passengers and security officials alike are on high alert for suspicious activity on board trains, after a heavily-armed gunman attempted to carry out a jihadist attack on a train in August, before being overpowered by other passengers.