The German government said on Monday that car companies would be expected to pass on relevant information to the Federal Motor Transport Authority so that it could assess whether emissions data may have been falsified in Germany and Europe.
"The automobile companies must work closely with the US authorities to clear this up," a spokesman for the German environment ministry said.
Meanwhile, US authorities said on Monday they would widen their probe to other manufacturers. The EPA and California officials said on Monday they would test the use of software in diesel vehicles from other manufacturers for similar possible violations.
Earlier, Volkswagen told US dealers to halt sales of some 2015 diesel cars. The Detroit News reported Friday VW dealers still had some 2015 diesel Jetta, Passat and Beetle cars for sale. A VW representative on Sunday confirmed the partial halt of sales.
