The US Justice Department has disclosed the filing of criminal charges against former Volkswagen chief executive Martin Winterkorn, accusing him of conspiring to cover up the German car maker's diesel emissions cheating.
The indictment, filed in secret in March, was unsealed in US District Court as Volkswagen held its annual meeting in Germany.
Winterkorn resigned days after the scandal over polluting vehicles in the US became public in September 2015.
U.S. Attorney General Jeff Sessions, Environmental Protection Adminstration chief Scott Pruitt and other senior Trump administration official issued statements criticising VW with the indictment, which marks a rare instance of a CEO being subjected to criminal prosecution for corporate behavior.
"If you try to deceive the US, then you will pay a heavy price," Sessions said.
In contrast with Volkswagen, no individuals were charged at Toyota in connection with its sudden unintended acceleration scandal or at General Motors for the cover-up of a deadly ignition switch defect.
The US government's decisions not to prosecute senior financial industry executives in connection with the 2007-2009 financial crisis also has drawn fire from advocates of tougher measures to deter corporate wrongdoing.
The US indictment of Winterkorn is likely to be largely symbolic.
As a German citizen, he is almost certain not to come to the US and to seek protection under German extradition law. The former CEO is also under investigation by German authorities.
Volkswagen settled criminal charges with the US Justice Department in 2017 and agreed to a $4.3 billion payment.
In total, VW has agreed to spend more than $25 billion in the US to address claims from owners, environmental regulators, states and dealers.
The company also has offered to buy back about 500,000 polluting U.S. vehicles. Many are now stored in parking lots around the US.
Volkswagen has been fighting to move past the emissions scandal, vowing to spend billions on a number of new electric vehicles as it has seen US sales rebound.
The indictment reopens the question of whether other senior VW executives knew about the scandal, which threatens to prolong the crisis.
Winterkorn, 70, is charged with four felony counts, including conspiracy to defraud the US, wire fraud and violating the Clean Air Act from at least May 2006 to November 2015 after the company admitted using illicit software that allowed Volkswagen diesel vehicles to emit excess pollution without detection.
Winterkorn in January 2017 told German lawmakers he had not been informed of the cheating early and would have halted it had he been aware, but he did not say when he first became aware of the issue.
A Volkswagen spokesman in Germany said the company "continues to cooperate with investigations" of individuals but would not comment on Thursday's charges.
