Prosecutors in Bavaria have found documents showing thousands of Audi vehicles were exported to Asian countries with the same identification number.

One VIN for multiple cars. Picture source: Reuters

To the litany of woes now facing the management of German carmaker Audi, you can add this mystery: prosecutors have turned up documents suggesting that thousands of Audis exported to China, Korea or Japan may have the same vehicle identification number.

This discovery, according to sources at the state prosecutor’s office in Munich, was made as investigators searched Audi corporate files for documents related to the dieselgate scandal. The raid in March came after the Transport Ministry accused Audi of cheating on emissions tests for 24,000 late model Audi A7 and A8 diesel vehicles, the company’s most luxurious products.

Audi later recalled the cars from all over Europe and upgraded their software to lower the amount of nitrogen oxide in their exhaust fumes, a major concern in German cities, where courts have ruled that local governments can consider banning diesel cars from the road on polluted days.

The investigators say Audi audit officials were scrutinizing the 'risk of discovery'

A spokesman for Audi said the company was unaware of any problem related to VIN numbers. "We are not aware of the fact the VIN numbers have been issued more than once," the spokesman said.

The VIN number is supposed to be a unique, 17-digit identifier for every car and truck that is stamped during production and stays with the car for the life of the vehicle, allowing owners to track things like its ownership history or accident record.

According to the sources, the documents were found during a search of Audi’s audit department. The investigators say Audi audit officials were scrutinizing the “risk of discovery” by assigning a traffic light code, meaning red for urgent, yellow for slow and green for less urgent.

Investigators admitted that they are mystified about what purpose would be served by producing vehicles with the same VIN number. Both German and EU laws stipulate that each vehicle be clearly identifiable by a unique VIN, that will remain uncopied for at least 30 years.

Imported Audis are especially prized in the Chinese market, where Audi has a joint venture with a Chinese firm to produce locally assembled cars. But the imported vehicles are more popular with affluent Chinese as a status symbol.

Jan Keuchel is a Handelsblatt correspondent covering investigations and the German legal system. Charles Wallace adapted this story to English. To contact the author: [email protected]