FRANKFURT — Volkswagen said on Tuesday that it was considering replacing Matthias Müller as chief executive as it grapples with a long-running diesel emissions scandal that has cost it billions of dollars, led to the imprisonment of two executives, and scarred the German carmaker’s reputation.
Mr. Müller, who took over after the company admitted in September 2015 that it had cheated on diesel emissions tests, has steadfastly denied any knowledge of the deception. The scandal involved the installation of illegal software in 11 million Volkswagen diesels, playing a major role in creating a serious air pollution problem in Europe.
Mr. Müller, an auto manager of the old school who spent his entire career at Volkswagen and its subsidiaries, struggled to move the company beyond the scandal, which was costly both to its reputation and to its bottom line.
And while he insisted he had no knowledge of the cheating, he was a high-ranking executive involved in product development at the same time that Audi and Volkswagen were concocting the illegal software and deploying it in vehicles. Mr. Müller also worked closely with some of the people under investigation over possible involvement in the emissions cheating conspiracy.
In a statement, Volkswagen said it was considering “a further development of the management structure of the group,” which could “include a change in the position of the chairman of the board of management.”
The scandal, and Volkswagen’s continued vulnerability to it, came into renewed focus after The New York Times reported in January that the company had helped to finance experiments on monkeys in a bungled attempt to show that exhaust from modern diesels was benign.
The experiments, in which monkeys were forced to breathe diesel fumes at a lab in Albuquerque, caused a furor in Germany and elsewhere. Chancellor Angela Merkel condemned the research, the German Parliament debated possible consequences, and animal rights activists demonstrated outside Volkswagen’s headquarters in Wolfsburg.
Mr. Müller promised to change Volkswagen’s corporate culture to be less authoritarian and less prone to the kind of behavior that led to the emissions cheating and other scandals. At the same time, he presided over a management board still dominated by people who, like himself, were products of that culture.
Critics said that, as a longtime insider, Mr. Müller lacked the credibility needed to force change within Volkswagen.