Hauptversammlung 2013 am 25 April in Hannover

Martin Winterkorn, left, next to now-ousted chairman Ferdinand Piech

Volkswagen Group CEO Martin Winterkorn has officially announced his resignation from the post, as the scandal involving VW and Audi diesel models in the United States – which have been found to have so-called “defeat devices” that help them cheat stringent federal air pollution tests – deepens further.

“I am shocked by the events of the past few days,” he said in a statement. “Above all, I am stunned that misconduct on such a scale was possible in the Volkswagen Group. As CEO I accept responsibility for the irregularities that have been found in diesel engines and have therefore requested the supervisory board to agree on terminating my function as CEO of the Volkswagen Group.”

Winterkorn added that the move was in the best interest of the world’s biggest car company, even though he was not aware of any wrongdoing on his part. “Volkswagen needs a fresh start – also in terms of personnel. I am clearing the way for this fresh start with my resignation.

“The process of clarification and transparency must continue,” he said. “This is the only way to win back trust. I am convinced that the Volkswagen Group and its team will overcome this grave crisis.”

Winterkorn’s resignation comes just weeks after he was confirmed to stay as head honcho (after a long leadership tussle with then-chairman Ferdinand Piech saw the ousting of the latter) until at least 2018, pending board approval; voting on the proposal was slated for Friday. It also follows mere hours after his public apology on video (as shown above), in which he vowed to “get to the bottom of this.”

To recap, the United States Environmental Protection Agency (EPA) has reportedly begun lobbying for a recall of roughly 482,000 VW and Audi vehicles in the country, due to an illegal code in their software to allow them to pass emissions tests, but otherwise produced “up to 40 times” the permitted levels of nitrogen oxides.

The group is facing possible fines of up to US$18 billion (RM79 billion) as well a criminal investigation by the US Justice Department, and has already seen its share prices plunge 23% on Monday, wiping out at least €15.6 billion (RM74.8 billion) of its market value. Want to know more about how VW allegedly managed to keep this quiet for so long, and how it finally got caught in the act? Read our in-depth story here.