It comes after environmental group DUH this week said tests carried out on a 2106 BMW 320d showed the car emitted higher harmful nitrogen oxide (NOx) levels on the road than in the lab, and well beyond legal limits.
"Investigators have begun a preliminary probe" into possible irregularities in BMW's emissions control systems, a spokeswoman from the Munich prosecutor's office told DPA news agency.
BMW has fiercely rejected the allegations, saying its vehicles had passed all regulatory tests and accusing DUH of subjecting the car to "atypical driving conditions".
A preliminary investigation is used by prosecutors to determine if there is enough evidence to suggest a crime has been committed.
Also Read
The German transport ministry has also said it will look into the allegations made by DUH.
The controversy marks the latest fallout from the "dieselgate" scandal that erupted when Volkswagen admitted in 2015 to using cheating software in 11 million diesel cars worldwide to dupe pollution tests.
Volkswagen is still grappling with the fallout from the scandal, which has so far cost the auto giant more than 25 billion euros (USD 30 billion) in fines, compensation and recalls.
Disclaimer: No Business Standard Journalist was involved in creation of this content