German and French prosecutors have broadened their investigations into VW emissions scandal.

French authorities have opened a formal probe into “aggravated fraud” over the use of diesel engine devices that gave misleading emissions results.

German prosecutors said the number of VW employees now under investigation has increased from six to 17.

Volkswagen, which said it is cooperating with all inquiries, had about 11 million cars fitted with the emissions devices.

Europe’s largest automaker is carrying out its own investigation, and has warned that the cost of car recalls and compensation was likely to run into billion of euros.

Paris prosecutors started preliminary inquiries in 2015, and confirmed on March 8 that three magistrates had been assigned to a formal probe.

Serious fraud office chief Nathalie Homobono said investigators had established that VW had cheated “with intent” by installing so-called engine software that reduced emissions under test conditions.

Meanwhile, German authorities said they had increased the number of VW employers under investigation to 17, but added that no former or current board members are involved, said Klaus Ziehe, from the state prosecutors office in Braunschweig, Lower Saxony.

Also on March 8, Reuters and the Financial Times were among media reporting that German insurer Allianz Global Investors, a VW shareholder, was close to filing a lawsuit against the carmaker following the fall in VW’s share price.

In January, the US Department of Justice filed a civil suit against VW, and the automaker faces a string of claims from customers that lawyers are likely to consolidate into a class action suit.

VW says it will not comment on specific details of the investigations.

Spokeswoman Jeannine Ginivan told the AFP news agency: “As previously stated, Volkswagen is not commenting on ongoing discussions with regulators. We are committed to regaining the trust of our customers and dealers and will continue to cooperate with all relevant government agencies.”