Top executives allegedly wanted to use the illegal software to cheat Hong Kong emissions regulations.

Former Audi engineer Ulrich Weiss has reportedly presented a potential bombshell document as evidence in a German labor court.

The document is said to indicate that Weiss' bosses may have opted to implement a defeat device in the Audi Q7 after finding that it emitted nitrogen oxide levels in excess of Hong Kong's strict regulations, according to a Forbes report citing a Bild reporter present at the court proceedings.

Weiss reportedly disagreed with the decision and demanded the order be put in writing, allegedly prompting powertrain development head Thomas Heiduk to sign off on the move after receiving approval from Audi board members Rupert Stadler, Ulrich Hackenberg, Werner Zimmermann and Michael Neumayer.

The timing of the document is also notable, dating back to July 2015 -- just months before the US cheating scandal came to light.

Weiss was suspended in November 2015 alongside other employees that may have played a role in the cheat. He was recently fired, just days after implicating Stadler, Audi's current CEO, in the illegal schemes.