A 2006 Powerpoint presentation detailing how Volkswagen could cheat its way past emissions testing has been uncovered as part of the ongoing investigation into the dieselgate scandal.
Two sources who have seen the presentation have told the The New York Times that the Powerpoint pack was prepared by a top technology executive at the German automaker.
Although the presentation set only contained a few slides, it detailed how regulators measure emissions output within a laboratory environment and suggested methods to work around them.
The presentation suggested that because regulators' methods were highly predictable, the company could utilise software code to detect these patterns and then enable the car's pollution equipment to produce compliant results.
Out on the road, and out of sight of regulators, cars equipped with engines from the EA189 family would emit oxides of nitrogen (NOx) at up to 40 times the rate permitted by US law.
According to the newspaper, the genesis of this presentation lay in the fact that Volkswagen's engineers had, by this time, realised that the emissions control equipment for the EA189 diesel engine family would wear out quickly if it was calibrated to comply with the US' more stringent NOx regulations.
In court documents sighted by the newspaper, lawyers for Volkswagen state that "the seemingly small danger of discovery may have been a factor in tempting the VW engineers to make the impermissible software alteration".
Back in 2006, equipment to measure emissions under real world conditions was expensive and rarely used by regulators. In recent years, though, the price of these parts has dropped significantly.
Indeed, it was a report published in 2014 by West Virginia University, and funded by the International Council on Clean Transportation, that unearthed a significant discrepancy between the laboratory and real world emissions of two Volkswagen models sold in the States.
This subsequently led to investigations by the United States' Environmental Protection Agency (EPA) and the California Air Resources Board (CARB).
In September 2015, Volkswagen publicly admitted that it had installed an emissions testing defeat device on almost half-a-million vehicles in the US with the EA189 TDI engine. Globally, there are 11 million Volkswagen group diesel cars equipped with the cheat software.