The German Federal Motor Transport Authority (KBA) has revealed that it has expanded its investigations into possible emissions testing manipulation to more than 50 vehicles across X brands.

Although the emissions scandal originally broke in the US, it quickly developed into an international issue for the German manufacturer. From the beginning, questions have been asked about whether Volkswagen was alone in manipulating its tests.

Graham Hill, director at GHA Finance, told Motor Finance that other manufacturers being caught cheating in emissions tests could bring the industry in general into disrepute.

The KBA said it was studying domestic and foreign vehicles. The models were chosen based on registration statistics in Germany and indications from third parties relating to conspicuous pollutant emissions.

The German regulator has been measuring both test condition readings and real life condition readings, and comparing the two. It said it had conducted about two thirds of tests.

So far, it said it had already identified increased nitric oxide levels in different driving and environmental conditions, and was evaluated the figures with the concerned manufacturers and approval authorities.