Audi cars with automatic transmissions have technology capable of distorting emissions when they are tested, Volkswagen said, as its luxury flagship is battling allegations over a reported discovery of a new cheat software device.

On November 6, German media first reported that certain automatic transmissions used in gasoline- and diesel-powered Audi cars had software that could determine whether the car was being tested by regulators and then switch to a more economical shift program in order to reduce carbon dioxide emissions. The Volkswagen Group has since confirmed that Audi does have transmissions that distort emission levels when cars are being tested.

German newspaper Bild am Sonntag reported last week that the California Air Resources Board discovered the software in an older Audi model over the summer, adding that the technology had been used in other diesel and petrol cars in Europe. Citing a confidential document, Sueddeutsche Zeitung reported over the weekend that the automatic transmission software would detect testing conditions (based on steering wheel movements) and adjust a car’s performance to emit less CO2 and nitric oxides. The car would operate at full performance during road driving, resulting in higher real-world emissions.

Volkswagen has been embroiled in an ongoing emissions cheating scandal after it admitted last year to installing so-called “defeat devices” on 11 million diesel cars. The software distorted emissions tests for nitrogen oxides, which cause health problems and contribute to global warming, and was installed on diesel models from Volkswagen, Audi, and Porsche. The newly discovered software distorted tests for CO2, which is the leading cause of global warming.

Volkswagen has not identified the Audi models that are affected by the software, but The Wall Street Journal reported over the weekend that it was installed on “top sedans and sport-utility vehicles,” including both diesel and gasoline-powered cars.