A new article by Handelsblatt Global claims the papers say Audi models sent to China, Korea and Japan may have the same 17-digit identifier, which is meant to be unique to each unit.
The report adds that the discovery was made during searches through the company's corporate files for documentation related to the long-running Dieselgate emissions scandal.
Despite the allegations, an Audi spokesperson is quoted by Handelsblatt, claiming the company has no knowledge of the issue.
"We are not aware of the fact the VIN numbers have been issued more than once,” the spokesman said.
European law stipulates that every vehicle, by any manufacturer, is required to have a unique VIN that makes it clearly identifiable, and needs to remain uncopied for at least 30 years.
At this stage, it's unknown why Audi would produce vehicles with the same VIN number, though it's reported that investigators claimed Audi's audit officials were scrutinising the 'risk of discovery' using a traffic light code - red for urgent, yellow for slow and green for less urgent.