It looks like Volkswagen’s huge diesel scandal may keep snowballing.
The German automaker said it is investigating whether more of its diesel cars may contain software that could be used to cheat emissions tests.
Volkswagen (VLKAY) had previously said as many as 11 million vehicles fitted with EA189 diesel engines could be affected. Now it’s investigating older versions of another engine, the EA288.
The car brands that have already been affected by the scandal include Volkswagen, Audi, Skoda and Seat, which are all owned by the Volkswagen Group.
The company has already issued recalls for 8.5 million diesel vehicles in Europe, and has been ordered to recall nearly 500,000 cars in the U.S.
Volkswagen in crisis: All you need to know
The scandal came to light last month when Volkswagen admitted it cheated on U.S. emission tests by installing software to make them appear cleaner than they were. Once on the road, the cars would pump out as much as 40 times the allowed level of nitrogen oxides.
Volkswagen is under criminal investigation in Germany, France, the U.S., and other countries. It has set aside 6.5 billion euros ($7.3 billion) to deal with the scandal, but analysts say the bill will be much higher.
Credit Suisse estimates the total cost could hit 78 billion euros ($88 billion) in a worst-case scenario.
Related: Volkswagen scandal in two minutes
–CNN’s Chris Liakos contributed to this article.