Volkswagen on Thursday announced the unexpected departure of compliance chief Christine Hohmann-Dennhardt, who only came on board a year ago to help clean up the German auto giant's image in the wake of the 'dieselgate' scandal.
In a statement, Volkswagen said Hohmann-Dennhardt was leaving "due to differences in their understanding of responsibilities and future operating structures within the function she leads".
The 66-year-old joined VW's board of management last January, when the company was reeling from its admission that it had installed cheating software in some 11 million diesel engines worldwide that made the cars seem less polluting than they were.
As head of VW's integrity and legal affairs, Hohmann-Dennhardt was tasked with burnishing the company's ethical credentials and reshaping its corporate culture.
Germany's Sueddeutsche Zeitung called her departure "a major setback" for Volkswagen as it seeks to win back customers' trust and turn the page on the crisis.
Citing company sources, the newspaper said Hohmann-Dennhardt had run into opposition over her efforts to shed light on how the emissions scam unfolded, clashing with top brass eager to draw a line under the saga.
Volkswagen earlier this month pleaded guilty to criminal charges over the pollution fraud, and has so far agreed to pay out more than $20 billion in fines and compensation to authorities, dealers and drivers in the United States.
But the firm remains embroiled in web of legal cases at home and abroad, with investigators especially eager to uncover to what extent VW executives knew about the cheating and helped cover it up.
In its statement, Volkswagen thanked Hohmann-Dennhardt for her "outstanding expertise" and said the company would "continue to press forward with changes to its way of thinking and working".
The former judge will formally step down on January 31, it added.
She will be replaced by VW's head of auditing, Hiltrud Werner.