An owner of a Mercedes BlueTEC diesel car has filed a class-action lawsuit in the US, accusing the car maker of knowingly programming its Clean Diesel vehicles to emit illegally high levels of nitrogen oxide.
Shares in Mercedes maker Daimler were down 3 percent at the bottom of Germany's blue-chip index in morning trade on Friday (local time) after news of the class-action lawsuit filed by Hagens Berman, which also has a lead role in class-action suits against Volkswagen.
Diesel car makers have been in the spotlight since Volkswagen admitted in September it had rigged US diesel emissions tests, and up to about 11 million vehicles worldwide could have illegal software installed.
The US Justice Department is suing the company for up to US$46 billion for alleged violations of environmental law.
Daimler has repeatedly denied it has rigged tests as well, and said on Friday it saw the suit, filed in the US District Court in New Jersey, as unfounded.
A spokesman said the car maker would examine the levels and defend itself against the suit.
Hagens Berman said in a statement on-road testing had shown Mercedes' Clean Diesel cars produced average on-road nitrogen oxide emissions that were 19 times above the US standard, with some instantaneous readings as high as 65 times more than the US limit.