FILM / INSIDE EYE: The real thing: Robert Harris, the author of Selling Hitler, on Schtonk]

I APPROACHED Schtonk], a self-proclaimed 'spoof' on the Hitler diaries affair, with a heavy heart. The one treatment which that extraordinary story does not require, I thought, is fictionalisation. Its fascination lies precisely in the fact it is all true. Then there was the title. The phrase 'a German comedy' is, for most of us, a contradiction in terms and the onomatopoeia of Schtonk] seemed particularly pregnant with heavy-footed, lederhosen-clad mirthlessness. And exclamation marks are generally a bad sign]

But I was wrong on both counts. Schtonk] is an enjoyable film, successful because, even at its most lampoonish, it always remains true to the facts, at least in spirit. Names are changed, incidents are telescoped and characters are merged, but the story is recognisably the same one that is told in Selling Hitler.

There are a dozen different versions of the Hitler diaries story - that it was a neo-Nazi conspiracy, that Heidemann was a gullible cat's-paw, that Kujau was working for Odessa - but Schtonk]'s is the same as mine. There was no grand conspiracy. There was no Nazi plot. Rather the Hitler diaries affair was the product of a chance encounter between two perfectly matched obsessives - a compulsive liar and a compulsive believer.

Theirs was a perfect symmetry of deceit, which grew exponentially. The forger deceived the journalist into believing the diaries were genuine. The journalist deceived the forger by pocketing half the money he should have handed over. Like The Pardoner's Tale or Volpone, it is a story in which the victims are as greedy, culpable and unlikeable as the supposed villains.

It is this that makes Schtonk] such a triumph. Freed from the need to follow every dot and comma of reality, it soars above the facts to achieve the level of a fable or morality play - a glorious and grotesque parable of cupidity, lust, obsession and ambition, made all the more darkly funny by being acted out in the shadow of Adolf Hitler. Old Nazis, slick journalists, hatchet-faced tycoons, even Hitler himself - all are treated with a savage, cynical, vulgar contempt reminiscent of the Berlin cabaret of the Weimar years. It makes a refreshing change to the conventional German reactions to any mention of Hitler: pious handwringing or touchy defensiveness.

To paraphrase Hugh Trevor- Roper: as I sat in the semi-darkness and the credits began to roll, my doubts gradually dissolved. I am now satisfied that Schtonk] is an authentically funny film, and that our standard views about German comedy will have to be revised.