The German state of Lower Saxony has filed a criminal complaint against Volkswagen AG after it was discovered that a file, which included copies of internal government memos on the carmaker's ongoing emissions scandal, had gone missing. The file was last seen on Oct.9 and it was reported missing the following Monday by the company's staff, the Associated Press (AP) reported, citing Anke Poerksen, a spokeswoman for the state government.

Lower Saxony, whose governor is on the German automaker’s supervisory board, is reportedly a minority shareholder in the company, AP reported. Poerksen also reportedly said that the staff in the company had been questioned, but there were "no concrete results" to locate the file. A report by Reuters said that the file did not have any documents from the supervisory board, but had printouts and duplicates of documents along with in-house notes on legal questions surrounding the scandal.

The Volkswagen emissions scandal came to light after a research team from the University of West Virginia discovered that the diesel cars produced by the company were equipped with defeat devices, which could hide the actual amount of carbon emissions from the vehicle during emissions tests. The research team said that when the cars were on the road, they would emit up to 40 times the permissible limit.

Volkswagen has so far hired U.S. law firm Jones Day to conduct an internal investigation into the emissions scandal and has said that the process would take “at least several months.” The company also promised to create a new committee to handle the crisis.

Last month, the company admitted that nearly 11 million cars globally were affected due to the defeat devices. Police raided the company’s Paris headquarters were last Friday to probe the scandal. Other countries like Canada, China, Germany and the U.S. have also launched national probes into the crisis.

Analysts from Reuters suggested that the company could face fines and legal costs up to 35 billion euros ($40 billion) in the U.S. and Europe due to the scandal, which has led to the decline of a quarter of its market value.