Three attorneys general on Tuesday directly challenged Volkswagen’s defense over its emissions deception, calling the decision to thwart pollution tests an orchestrated fraud that lasted more than a decade, involved dozens of engineers and managers and reached deep into the company’s boardroom.

The accusations, leveled in lawsuits by New York, Massachusetts and Maryland, contradict Volkswagen’s portrayal of the deception, representing a new threat to the carmaker’s finances, reputation and management. For the first time, the suits connected Volkswagen’s chief executive, Matthias Müller, to the scandal, saying he was aware of a 2006 decision to not outfit Audi vehicles with equipment needed to meet American clean-air standards.

Volkswagen, which admitted late last year to equipping 11 million vehicles worldwide with software to cheat emissions tests, has maintained that the deception was limited to a small group of people. The company has said top management was not aware of the cheating software, known as a defeat device.

But the New York civil complaint, drawing on internal Volkswagen documents, emails and witness statements, depicts a corporate culture that allowed a “willful and systematic scheme of cheating.” The evidence paints the most detailed picture yet about how the deception unfolded and who was responsible.