It's understood the man arrested is Zaccheo Giovanni Pamio, who was head of thermodynamics at Audi’s engine development department in Neckarsulm, Germany, between 2006 and 2015.
Pamio allegedly went down this route because of the Volkswagen Group's demanding culture, and decisions made elsewhere within the company, which limited the space allocated to the car's AdBlue reservoir. The space freed up by a smaller AdBlue tank, it's said, was used for the car's high-end sound system.
The AdBlue solution, when added to diesel engine exhaust, helps to remove NOx. If guided by accurate emissions data, Audi drivers would be required to refill their AdBlue tanks outside of regular scheduled services. This, it's alleged, Audi feared would turn customers away from its TDI vehicles.
To get around this, Audi decided to restrict AdBlue usage and illegally pollute more than allowed, as well as operating in a compliant mode during emissions testing situations.
The New York Times believes US authorities are targeting lower level employees in the hopes they will provide testimony against higher level executives. Pamio reportedly presented the plan and outlined details about the scheme to at least one member of Audi's management board.
Pamio is the eighth person to be indicted over the Dieselgate affair by the FBI and the US' Environmental Protection Agency. Pamio is a citizen of Italy, while the others are Germans. Germany currently refuses to extradite its own citizens to the USA.
Two have been arrested, though. James Liang, an engineer at the company's Californian testing facilities, lives in the States, and has pled guilty to lying to and defrauding the US government, and violating the Clean Air Act.
Oliver Schmidt, an emissions compliance executive for the company, was arrested in January while on a business trip to the States. He faces similar charges to Liang.