A German film director best known for his adaptations of bloody video games has sparked widespread revulsion with his upcoming film about the horrors of the Holocaust.

Uwe Boll, who has been described as the world's worst film director and a "schlockmeister", said he felt it was time to present the Nazis' crimes in their "full horror" in his film Auschwitz.

His aim, he said, was to allow audiences to finally grasp the "real, everyday truth" of the Third Reich's atrocities.

Some critics have already vowed to boycott the film, having seen a gruesome teaser trailer – users must prove they are 18 before watching the clip on YouTube but even for adults it makes very grim viewing.

In the excerpt, the 45-year old filmmaker appears as an SS officer outside a gas chamber inside which prisoners are suffocating as they hammer in vain on the locked door.

Other scenes show prisoners being loaded into ovens and having their teeth pulled.

Critic Sophie Albers wrote in Stern magazine: "The words Auschwitz and Uwe Boll in one breath rightly leads one to fear the worst," adding that the film provoked "outrage, confusion and panic".

Tom Goldman, a critic with videogaming magazine the Escapist, said the film was "disturbing and gruesome" and was likely to push moviegoers "over the edge".

Forced on to the defensive even before a release date for the film has been set, Boll said in an interview with Die Welt it was "high time" to make a film which showed the "real Auschwitz".

He said that audiences had for too long been softened by "special story films" about the Holocaust "like Life is Beautiful or Schindler's List".

He said such films no longer had the ability to reach young people and that it was his duty as a German to make the film as a way of confronting the past.

"Every German is obliged to ensure that the Holocaust is not forgotten," he said.

"For a director like me who is known for his explicit depictions of violence, it's my duty to use precisely this talent to show people the atrocities of the Nazis."

Boll is best-known for video game adaptations such as BloodRayne and Alone in the Dark, as well as films about Vietnam, Darfur and 9/11, all of which have received very mixed reviews.

He once said he would stop making films if a million people signed a petition against him. An online version of the petition had more than 360,000 signatures today.

Boll told Stern: "Of course reality is unbearable, but we're talking here about something that was like an abattoir."

He said the killing scenes were "restricted" to 20 minutes, and that the rest of the film showed everyday life at the camp and included documentary footage.

Boll, whose most recent film Max Schmeling was about the boxer of that name, has submitted a rough cut of Auschwitz to the Berlin film festival, the Berlinale, and said he was waiting to hear if it had been accepted for the February 2011 event.

The film, which is currently in post-production, is due for general release early next year.

Boll compared his film to Alain Resnais's 1955 documentary Night and Fog.

"His film is also incredibly brutal but nevertheless it's the best film ever made about Auschwitz," he said.