The German government has announced it will re-test 30 cars that emit CO2 levels it considers "inexplicably high," according to a new report fromAutomotive News.Initially, the German government only tested diesel vehicles for defeat devices after Volkswagen Group admitted to manipulating emissions tests using engine management software.

Though the test looked for high NOx emissions, officials were surprised that many of the cars tested also produced high levels of CO2. A spokeswoman for the German transport ministry toldANthat out of 53 vehicles tested, 30 of them "were showing inexplicably high CO2 emissions," which has led authorities to conduct another round of testing. The cars being re-tested and their respective manufacturers weren't named by the German transport ministry, but the spokeswoman did say that the committee investigating the matter will present a CO2 report following the results.

The KBA motor transport authority said that only Volkswagen has used the now-infamous type of defeat device to cheat emissions testing, but it will continue investigating other automakers in search of answers to how certain cars emit considerably higher emissions outside of testing conditions. In addition to Volkswagen Group vehicles, the KBA will also be testing cars from Ford, Mercedes-Benz, FCA, Renault, Peugeot, Toyota, BMW, and Opel.