The supplier of Volkswagen's emission-rigging software warned Volkswagen against the idea of emission-cheating about eight years ago.
The supplier company, known as Bosch, is reported to have explained in a memo to Volkswagen that the use of such emission-cheating software would go against the law.
As confirmed by an investigation by internal German newspaper Bild am Sonntag, a letter written in 2007 from the parts firm signaled against the deployment of the software.
Bosch delivered the software to Volkswagen on grounds that Volkswagen would use it for testing purposes only and not for driving mode as unveiled to be the case.
According to German newsreporting site Frankfurter Allgemeine Sonntagszeitung, a Volkswagen technician had initially in 2011 raised concerns about unlawful practices in the company.
Aside from Volkswagen, Bosch confirmed that it formerly supplied and continues to supply components for the after-treatment of exhaust to various manufacturers. This has fueled possibilities of other car manufacturers being involved in emission-cheating as well.
Meanwhile, German prosecutors have started investigating former Volkswagen CEO Martin Winterkorn. Winterkorn who resigned recently faces "allegations of fraud in the sales of cars with manipulated emissions data."
The emission-cheating has affected over 11 million cars globally 2.1 million being Audi models. Volkswagen admitted this but has not yet said if the affected vehicles will have to be refitted or recalled.
Volkswagen, after admitting to cheating tests of diesel emissions in the United States, faces the biggest business scandal in its 78-year history. Because of this, economists have disclosed that the Volkswagen Company could face trouble seeking funding for its future leasing deals.