The UK Department of Transport said on Friday (13 January) it was urgently seeking details over allegations Fiat Chrysler Automobiles (FCA) cheated emission tests.

On Thursday, the US Environmental Protection Agency opened a probe into the carmaker, suggesting approximately 104,000 vehicles produced by Fiat Chrysler "may be liable for civil penalties".

The company is accused of illegally using a hidden software that would allow excess diesel emissions to remain undetected.

"We are urgently seeking further information from the US Environmental Protection Agency [...] and will also be seeking information from the manufacturer regarding vehicles in the UK market," said a spokesman for the Department of Transport.

US authorities alleged that FCA violated the Clean Air Act by installing and failing to make public "engine management software" in the 3.0-litre diesel engines of the Jeep Grand Cherokee sports utility vehicle, model years 2014, 2015 and 2016, and the Dodge Ram 1500 pickup truck, both sold in the US.

The software is believed to have artificially lowered the amount of nitrogen oxide (NOx) produced by the engines during test conditions, then allowing the engines to produce more than the legal limit when driven normally. The EPA said it was investigating whether the software can be classified as a form of "defeat device", which would be illegal.

Sergio Marchionne, the group chief executive, angrily dismissed the allegations on Thursday, insisting there was no foul play involved and that the carmaker never attempted to create or utilise softwares to allow it to cheat emission tests.

The probe into FCA came just a day after German carmaker Volkswagen has agreed to a $4.3bn (£3.5bn, €4bn) settlement with US prosecutors over its diesel emissions cheating.

The penalty is the largest ever fine imposed on an automaker in the US and includes a criminal fine of $2.8bn along with civil penalties of $1.5bn.

However, speaking to the BBC's Today programme, John German from the International Council on Clean Transportation, said a distinction should be drawn between the two investigations.

"VW had software embedded that looked for the actual test cycle used for regulatory purposes, and when they recognised it they turned the emissions controls on, and all other times they shut the emissions controls off," he said.

"So in the real world, the emissions controls were basically off all of the time.

"FCA has not done this. What they're doing is they're looking at things like vehicle speed, vehicle acceleration, and so they're shutting the emission controls off some of the time in the real world, but not all of the time."

The UK is facing legal action from the European Union over its failure to act against VW.