The investigation allegedly revealed emissions from some of the manufacturer's models were several times higher than regulatory limits, and FCA has been referred for possible prosecution while investigations into other car brands continue. Both Volkswagen and Renault have previously been referred to French prosecutors.
Results from a testing programme carried out by French regulators last July showed that the Jeep Cherokee emitted eight times the NOx limit during lab tests, while the Fiat 500X emitted almost 17 times the limit in road testing, according to the report.
An FCA spokesman told Reuters that its diesels were fully compliant with applicable emissions requirements and said that while it had reservations about the tests carried out, it will cooperate with the investigation.
Cheat devices in Europe and America
Earlier this year, it was reported that more than 700,000 FCA Chrysler Automobiles cars in Europe and America are potentially fitted with emissions-cheating software, with 600,000 of these in Europe alone, according to a report in the Financial Times.
The US's Environmental Protection Agency (EPA) has publically accused Fiat Chrysler Automobiles (FCA) of using cheat software akin to that used by Volkswagen in the dieselgate emissions scandal, according to Reuters.
FCA cars accused of cheating include the Dodge Ram 1500 and Jeep Grand Cherokee, which are fitted with the manufacturer's 3.0-litre diesel engine – more than 104,000 of which have been sold in the US – with cars sold since 2014 alleged to be fitted with software which ‘allowed excess diesel emissions’.
According to the Society of Motor Manufacturers & Traders (SMMT), the number of cars fitted with the implicated 3.0-litre diesel engine in the UK is 4235, although it's not yet clear if all applications of this engine have the software. Nevertheless, the BBC reports that the Department for Transport (DfT) has asked the EPA for further details on the issue.
FCA has been mentioned in emissions controversies; Fiat had to answer to German regulators last spring, before being accused of using an emissions cheat device in October.
In the midst of the Volkswagen emissions scandal at the beginning of 2016, FCA also released an unprompted statement saying that its cars do not cheat emissions tests.
Volkswagen’s US emissions scandal has involved the arrest of two senior employees and charges held against five more, who are believed to be in Germany. The manufacturer agreed to pay a $4.3 billion (£3.55bn) fine to US regulators as a settlement.
FCA released the following statement in reaction to the EPA's accusation: "FCA US is disappointed that the EPA has chosen to issue a notice of violation with respect to the emissions control technology employed in the company’s 2014-16 model year light-duty 3.0-litre diesel engines.
"FCA US looks forward to the opportunity to meet with the EPA’s enforcement division and representatives of the new administration to demonstrate that FCA US’s emissions control strategies are properly justified and thus are not defeat devices under applicable regulations and to resolve this matter expeditiously."