US states sue Volkswagen over emission scandal
Three US states have taken legal action against Volkswagen in the wake of the carmaker's emissions scandal.
New York, Massachusetts and Maryland all filed lawsuits on Tuesday.
New York's Attorney-General called the use of "defeat devices" a "widespread conspiracy" and a "cunningly cynical fraud" committed by all levels of VW management.
The company said the allegations were "not new" and that the carmaker had been cooperating with US authorises.
"It is regrettable that some states have decided to sue for environmental claims now, notwithstanding their prior support of this ongoing federal-state collaborative process," VW said.
Last month, it announced a $15.3bn (£11.6bn) settlement with federal regulators, several states and thousands of owners of the affected vehicles.
That deal included a "partial settlement" with New York and 43 other states worth $603m.
Volkswagen admitted last year to installing "defeat devices" that disguised the level of emissions from its diesel cars when the vehicles underwent environmental testing. The devices were placed in 11 million cars worldwide.
Massachusetts Attorney-General Maura Healey said VW damaged the environment and "plotted a massive cover-up to mislead environmental regulators".
"With today's action, we want to make clear to all auto manufacturers that violating laws designed to protect our environment and our public health is unacceptable and will be punished with significant penalties," she said.
The lawsuits accuse VW executives, including former chief executive Martin Winterkorn, of covering up the scandal for over a decade.
The lawsuits publically identify management officials who knew that many diesel models could not meet clean-air standards without reducing their level of driving performance.
When regulators began to investigate the emission issues, VW officials gave an overly technical presentation designed to confuse authorities, the lawsuits alleged.
New York Attorney-General Eric Schneiderman said the company had a "culture of deeply-rooted corporate arrogance, combined with a conscious disregard for the rule of law".
The New York legal action claims that VW chief executive Matthias Mueller was part of the cover-up as he was head of project management at Audi at the time. It claimed that in 2006 he decided not to equip certain Audi vehicles with the parts needed to meet US environmental standards.
"It's clear Mr Muller was aware of the problem at least from July 2006," Mr Schneiderman said in a press conference.
The lawsuits also alleged that members of VW's engineering department deleted incriminating data in August 2015. Mr Schneiderman said some of that data had since been recovered.
Speaking at a press conference the New York and Massachusetts attorneys-general stressed the importance of the lawsuit to send a message to other carmakers not to defraud the US public.
VW also faced legal action from shareholders and criminal investigations in many other countries.