A top U.K. and global law firm confirmed Thursday that it is filing a lawsuit against Fiat Chrysler Automobiles (FCA) for up to half million of its vehicles sold in the U.K. and believed to be equipped with illegal emissions-cheating devices.

The ex-CEO of a world-renowned German car manufacturer will this week become the first of the company’s former executives to stand trial over the Dieselgate emissions-cheating scandal.

A German court announced on Wednesday that formerVolkswagen CEO Martin Winterkorn and four other ex-employees will face the judge for their role in the so-called ‘dieselgate’ scandal in which the car producer was caught cheating on emission tests.

Germans prosecutors pressed on Thursday fraud charges against three former board members and a retired senior employee of the automobile manufacturer Audi for being involved in the manipulation of engines to make them appear spewing less harmful pollutants.

Paris-based carmaker PSA Group allegedly used a fraudulent software on almost two million vehicles to manipulate diesel emissions tests, French newspaper Le Monde revealed on Friday.

Volkswagen, Audi, BMW, Porsche and Daimler are under investigation by the EU and German authorities for forming a secret ‘economic cartel’ in the 1990s to collude on diesel emissions, after Daimler blew the whistle, media reported Monday.