Controversy is raging in Berlin over a film that portrays Hitler’s days as a young, struggling artist. Its stars and director defend it to Peter Culshaw.

John Cusack plays Max Rothman, a Jewish art-dealer who once wanted to be a painter but lost an arm in the war and now runs an avant-garde gallery. He takes an interest in the work of Corporal Hitler, encouraging him to express his doubts and fears on canvas. While those around Rothman, an urbane bohemian with a complicated love life, want nothing to do with the poisonous young corporal with his half-baked theories of racial purity, Rothman takes pity on him - “He had a bad war,” he says. And, though the young Hitler is a bad artist, Rothman senses some potential for greatness in him, telling him that he has “something rustling behind your curtain”.

“You know intellectually that Hitler was born of a mother and father, was human and wandered the streets of Munich,” says Cusack, “but we’d prefer it if he lived in a cave drinking blood and breathing fire.”