Attorney General Hector Balderas filed the lawsuit in state district court late yesterday. He alleges Volkswagen, Audi, Porsche and their US subsidiaries violated New Mexico's air quality standards and engaged in deceptive marketing to pass off certain diesel models as clean and efficient.

"Supported by a massive advertising campaign, defendants claimed that superior engineering allowed their cars to perform better, consume less fuel and emit fewer harmful pollutants than diesel cars of the past, making them a great fit for eco-conscious consumers. In fact, the complete opposite was true," the lawsuit says.

Dozens of state attorneys general have teamed up for a civil investigation of VW. Others are conducting separate inquiries.

Earlier this month, the US Justice Department sued on behalf of the federal Environmental Protection Agency. That action alone could potentially expose VW to more than USD 20 billion in fines under the Clean Air Act.

A spokeswoman for VW declined to comment on New Mexico's lawsuit.