Auto maker Fiat Chrysler Automobiles NV (NYSE:FCAU) has been alleged for not informing establishments about software that controls emissions in thousands of company’s diesel vehicles.

The US Environmental Protection Agency (EPA) announced that the company broke the law by fitting, but not revealing the technology in more than 100,000 Jeeps and Dodge vehicles.

Fiat Chrysler Automobiles NV (NYSE:FCAU) boss Sergio Marchionne said the firm had done nothing illegal.

“There was never any intent of creating conditions that were designed to defeat the testing process. This is absolute nonsense,” he added.

The EPA said in a statement Fiat Chrysler may have to pay fines of about $44,500 per car, which would mean a total of about $4.6bn.

According to the EPA, the 104,000 vehicles affected were 2014, 2015 and 2016 model years of the Jeep Grand Cherokee SUV and Dodge Ram truck.

Between “one-sixth and one-seventh” of the vehicles were sold in Europe, with the rest in the US, according to Fiat Chrysler.

Furthermore EPA said in a statement that almost eight types of emissions control software on the car had not been revealed to the agency and some of the software seemed to make cars perform in a different way during emissions tests.

“Failing to disclose software that affects emissions in a vehicle’s engine is a serious violation of the law, which can result in harmful pollution in the air we breathe,” said EPA official Cynthia Giles. “All automakers must play by the same rules.”

Moreover Fiat Chrysler announced it would prove that its emissions control strategies were justified and thus were not “defeat devices” designed to get around emissions tests.