The U.S. Justice Department has filed a civil suit against Volkswagen AG for allegedly violating environmental rules through its use of software to cheat emissions tests. According to senior officials, Volkswagen could face up to $90 billion (AED 330 billion) in penalties. The civil lawsuit reveals the expanding number of allegations against the company, which first admitted in September to installing cheat devices in several of its 2.0 liter diesel vehicle models. The U.S. lawsuit also alleges that Volkswagen fitted similar rogue emissions controls in many of its 3.0 liter diesel models, including the Audi Q7, and the Porsche Cayenne. The civil lawsuit does not prevent the Justice Department from pursuing criminal charges against the car maker.