Volkswagen AG said Thursday that the emissions cheating scandal dated back to 2005 after the automaker realized the diesel engines they were aiming to promote in the United States would not meet the country’s clean air standards, the New York Times reported. The company, however, continued cheating even after its technology to pass emissions tests improved.

“It proves not to have been a one-time error, but rather a chain of errors that were allowed to happen,” Hans-Dieter Pötsch, chairman of Volkswagen’s supervisory board, said, according to the Times. Pötsch also said that defending the company’s market position following the scandal, which broke in September this year, will be “no easy task” and "winning back trust is our top priority,” Reuters reported

Volkswagen suspended nine managers following the scandal. However, Pötsch did not say if the German automaker would suspend more officials, but added that its investigations would be wide, the Associated Press (AP) reported.

The investigation has so far examined data from laptops, phones and other devices of 400 employees, and over 2,000 others were informed not to delete any data, Pötsch reportedly said. External auditors checked 102 terabytes of data, which Pötsch said was the equal to 50 million books, according to AP.

"I'm not saying all of those people are under suspicion, but what it means is that on computers, sim cards, or USB sticks there might be information that could be important," Pötsch said. "We still believe that only a comparatively small number of employees was actually actively involved in the manipulations."

Volkswagen has apologized over the scandal repeatedly, but has yet to provide enough information on the scandal. About 11 million diesel vehicles were rigged to pass emissions tests.