BERLIN (REUTERS) - Volkswagen AG executive Oliver Schmidt, who is due to be sentenced this week in connection with the carmaker's emissions scandal, has written to the judge to say he feels "misused" by the German company, a newspaper reported on Sunday (Dec 3).

Schmidt pleaded guilty in August in the US District Court in Detroit to wrongdoing connected to a massive diesel emissions scandal that has cost Volkswagen as much as US$30 billion (S$40 billion). He is due to be sentenced on Dec 6.

"I must say that I feel misused by my own company in the diesel scandal or 'Dieselgate'," Schmidt wrote to US judge Sean Cox, according to a copy of the letter published by Germany's Bild am Sonntag newspaper.

A Volkswagen spokesman declined to comment, citing the ongoing proceedings.

Under a plea agreement, Schmidt faces up to seven years in prison and a fine of between US$40,000 and US$400,000 after admitting to conspiring to mislead US regulators and violating clean air laws.

In March, Volkswagen pleaded guilty to three felony counts under a plea agreement to resolve US charges it installed secret software in vehicles to evade emissions tests.

US prosecutors have charged eight current and former Volkswagen executives.

Schmidt was in charge of the company's environmental and engineering office in Auburn Hills, Michigan, until February 2015, where he oversaw emissions issues.

In the letter to the judge, he said he had agreed to follow a script, or talking points, agreed by Volkswagen management and a high-ranking lawyer, at a meeting with Alberto Ayala, a California Air Resources Board executive.

"In hindsight, I should never have agreed to meet with Dr Ayala on that day," he wrote.

"Or better yet, I should have gone to that meeting and ignored the instructions given to me and told Dr Ayala that there is a defeat device in the VW diesel engine vehicles and that VW had been cheating for almost a decade. I did not do that and that is why I find myself here today."

After being informed of the existence of the emissions software in the summer of 2015, according to his guilty plea, Schmidt conspired with other executives to avoid disclosing "intentional cheating" by the automaker in a bid to seek regulatory approval for its model 2016 VW 2 litre diesels.