CREDIT: AP Photo/Mark Lennihan. Massachusetts Attorney General Maura Healey, right, joined by New York Attorney General Eric Schneiderman, discusses a lawsuit against Volkswagen, Tuesday, July 19, 2016, in New York.

The largest fine in automobile history is not going to be the end of the story for Volkswagen.

Attorneys general for New York, Massachusetts, and Maryland announced Tuesday they are suing the company for fraud, saying that the Volkwagen’s installation of defeat devices to thwart emissions testing was part of a “willful, systemic scheme.”

“Today’s suit and the nine-month investigation that led to it are designed to hold Volkswagen accountable for their actions,” New York Attorney General Eric Schneiderman said at a press conference Tuesday. “What we found in our investigation was shocking and reveals a cunningly cynical fraud at the heart of this scandal.”

Last fall, the EPA charged Volkwagen with violating the Clean Air Act. Volkswagen’s so-called clean diesel cars were programmed to be able to pass emissions tests, even though in real-life driving situations, they emitted up to 40 times more ntitrogen-oxide (NOx) compound emissions than allowable under EPA regulations. Two subsidiaries, Audi and Porsche, were also found to have installed defeat devices.

Investigators believe the company pursued this strategy after it was unable to meet U.S. air quality standards by using diesel while still achieving fuel efficiency and providing desired performance capabilities. NOx compounds react with sunlight to cause ground-level ozone, which is tied to increased asthma and other respiratory and cardio health impacts.

Ironically, as Schneiderman noted, during the period of 2009-2014, when Volkswagen was willfully deceiving regulators, the company was simultaneously marketing its cars as good for the environment. In 2010, Audi’s A3 diesel model won Green Car Journals “Green Car of the Year” award. Audi ran a Super Bowl ad touting the car’s environmental bona fides.

According to Schneiderman, it was the second-most watched ad in history.

Audi’s tagline at the time was “Truth in Engineering.”

“This clean diesel was no more than a dirty cover up,” Massachusetts Attorney General Maura Healey said at the press conference Tuesday announcing the filing.

When the allegations first came out, Volkswagen said the deceit was the work of “rogue” engineers, but the attorneys general’s investigation allegedly will show that “dozens” of employees, knew about the fraud, including the former CEO, Matthias Müller. According to the New York Times, this is the first suit to connect the executive to the scandal.

“Employees actually undertook to destroy incriminating docs,” Healey said. “Volkswagen worked hard to cover up the existence of defeat devices.”

Under the terms of a previous settlement, the company has already agreed to pay $2.7 billion in environmental remediation, another $2 billion in clean-technology investment, and more than $10 billion in a consumer buyback program.