A BMW logo is seen on a car at the International Auto Show in Mexico City, Mexico November 23, 2017. REUTERS/Henry Romero

MUNICH (Reuters) - Munich prosecutors have opened a preliminary inquiry into allegations made this week by Germany’s main environmental lobby group that a BMW diesel model is fitted with engine software capable of cheating on emissions tests.

BMW’s 3-Series 320d car, designed to comply with the latest Euro 6 emission standards, was found to have breached permitted nitrogen oxide (NOx) emission levels by up to seven times the legal limit in a series of road tests while emissions remained below the limit in a set of static roller-bed tests, Deutsche Umwelthilfe (DUH) alleged on Tuesday.

Munich prosecutors on Wednesday said they had initiated a “preliminary examination”, without being more specific, after the German Transport Ministry had said on Tuesday that the KBA motor vehicle regulator would look into the accusations.

A BMW spokesman said the company had taken note of the move by Munich prosecutors but remained convinced that the vehicle in question complied with all emission requirements.

The company was considering its options with regard to the accusations, the spokesman added.

The DUH had said that in the roller-bed tests, which like its road tests were not independently verified, the BMW 320d’s NOx emissions remained significantly below the 80 milligrams per kilometer limit at normal speeds and also when the speed was increased by 10 percent.

Volkswagen's VOWG_p.DE emissions test-cheating scandal two years ago has since spilled over to the wider German vehicle industry with its luxury division Audi and Daimler the subjects of criminal investigations.