Around 98,000 petrol cars count among the 800,000 Volkswagen vehicles found to show irregularities on their carbon emission levels, Germany's Transport Minister Alexander Dobrindt said Wednesday.

"Among the affected vehicles, 98,000 are petrol cars," Dobrindt told parliament, a day after VW said an internal probe had found some of its vehicles were releasing more of greenhouse gas CO2 than previous tests had shown.