Volkswagen's top-of-the-range automaker Audi said Monday that 2.1 million of its diesel cars worldwide are fitted with the sophisticated software enabling them to cheat emission tests.

In Germany alone, 577,000 vehicles were affected and 13,000 in the United States, an Audi spokesman said. VW sparked global outrage last week when it admitted that 11 million of its diesel cars are fitted with so-called defeat devices that activate pollution controls during tests but covertly turn them off when the car is on the road.