A car containing several gas cylinders was discovered close to the Notre-Dame cathedral in central Paris last Saturday night and its owner, now in custody, wason an intelligence services watchlist of people suspected of religious radicalisation, police officials said.
One official said the car's hazard lights were flashing when it was found and that it contained seven gas cylinders, one of them empty and placed on the front passenger seat.
There was no detonating device present, one of the officials added.
Documents with writing in Arabic were also found in the car.
More than 200 people have been killed in terror attacks over the past year-and-a-half in France.
France remains on maximum alert after calls by the Islamic State group for followers to attack the country, which is bombing the militant group's bases in Iraq and Syria.