A Chicago law firm has begun a class action lawsuit against Volkswagen over the "defeat devices" used to fool exhaust emissions tests.
Robert Clifford, partner at Clifford Law, said it had been filed at a district court in northern Illinois.
He said the impact on consumers was "massive".
It comes as the German company's boss is under increasing pressure ahead of crisis talks.
Martin Winterkorn will meet members of the firm's board later, with his job under threat & the VW'sÂ value having taken a massive dent.
The embattled car firm admits software used to rig exhaust tests may have been in some 11 million vehicles worldwide & now faces a criminal investigation in the US & further probes in countries including Germany, France & South Korea.
New York Attorney General EricÂ SchneidermanÂ also confirmed he had opened an investigation, adding: "No company should be allowed to evade our environmental laws or promise consumers a fake bill of goods."Â
US authorities say the firm deliberately circumvented clean air rules on diesel cars through the use of software which was triggered when cars were undergoing exhaust tests.
The so-called "defeat devices" meant that true emission levels, as much as 40 times the level legally allowed in the US, were hidden.
Chief executive Martin WinterkornÂ has apologised yet has given no undertaking to resign.
"I am endlessly sorry that we have disappointed this trust. I apologise in every way to our customers, to authorities & the whole public for the wrongdoing," he said in a video message.
"We are asking, I am asking for your trust on our way forward," he said. "We will clear this up."
His words were followed by reports that he has lost the confidence of the German manufacturer's shareholders, however, as stocks fell 20% on Tuesday.
Volkswagen was due to hold a supervisory board meeting on Friday.
But it is now understood that Mr Winterkorn could find himself appearing before a select group of board members as early as Wednesday afternoon.
The company has set aside â‚¬6.5bn (Â£4.7bn) to cover costs related to the issue & has warned the bill could rise.
At least 482,000 cars will be recalled & VW could face financial penalties totalling more than $18bn in the US alone.
There are fears many cars could be recalled in the UK also.
Source: “Sky News”