The FBI arrested Volkswagen executive Oliver Schmidt over the weekend on charges of conspiracy to defraud the US relating to the ongoing Dieselgate emissions scandal.

Schmidt headed VW's regulatory compliance office in the US from 2014 to March 2015. The FBI's official Criminal Complaint states that during that time VW employees -- Schmidt included -- knowingly installed secret "defeat device" software in 475,000 diesel cars in the US, hiding during emissions testing the fact that those cars emitted up to 40 times the legally allowable pollution levels when on the road.

The complaint asserts that by knowingly installing this secret cheat software, Schmidt and VW conspired to defraud the US by impairing and impeding the Environmental Protection Agency and violating the Clean Air Act, leading to the arrest on Saturday.

Schmidt is due to appear before a Federal Court in Miami on Monday.

The news comes just as we were thinking that Volkswagen was nearing the end of the Dieselgate controversy here in the US and in Europe. The automaker did not comment on the arrest or its ramifications during its press conference here at the Detroit auto show, instead focusing on the launch of the new gasoline-powered 2018 Tiguan and Atlas R-Line SUVs and the electric ID Buzz concept.