"A motor vehicle manufacturer whose unlawfully manipulated vehicles are resold in other member states may be sued in the courts of those states," the EU Court of Justice in Luxembourg said on Thursday
US authorities banned the affected cars after the cheat software was discovered, triggering claims for compensation.
Around 400,000 diesel owners have joined a mass lawsuit against Volkswagen over the group's 2011 admission to emissions cheating
Meanwhile, prosecutors are investigating VW on suspicion of fraud, stock market manipulation and false advertising
US prosecutors have charged eight current and former Volkswagen executives. Six of those remain at large
VW pleaded guilty to three felony counts as part of an agreement reached with Justice Dept
Piech gave testimony to lawyers of US law firm Jones Day last April and to German prosecutors
An intensive investigation into the manipulation of diesel emissions tests began more than a year ago
German automaker says it will begin buying back the vehicles in mid-November