A warts-and-all portrayal of the revered Russian writer Ivan Bunin – as a bullying, drunken egotist – is being hailed as the most important film to come out of Russia this year. So why did the authorities try to block it? Amelia Gentleman reports.

When Aleksei Uchitel presented a screenplay about the Russian emigre writer Ivan Bunin to the State Cinema Financing Commission, funding was refused by dismayed committee members – distressed by his exposure of the writer's tangled love life. Uchitel had made a grave mistake in underestimating how protective Russia remains of its artistic icons, inclined to treat even the most disreputable writers with devout, unquestioning respect.

Instead of a reverent biographical work, portraying Bunin assiduously scratching away at his short stories, His Wife's Diary shows him wholly preoccupied by his young mistress, callously neglecting his wife in an uncomfortable menage-a-trois at his South of France villa. Worse still, it displays the Nobel prize-winning writer, who died in 1953, as a bullying, drinking egotist, sent into a decline by the departure of his lover (some 40 years younger than him) for another woman. As his behaviour deteriorates, he abandons his writing and takes up instead with a local woman, who may or may not be a prostitute, before falling in love with a dog.

So far did the film stray from the Soviet-era glorification of Russia's classical writers on film that the Commission tried to block it. Only a last-minute intervention from the Film Minister, who loved the script, saved the project and provided the necessary funding.

Since its premiere in Moscow last month, His Wife's Diary has been hailed as the most important film to come out of Russia this year and has been put forward as the country's entry for the best foreign-film Oscar. Dunya Smirnova's screenplay has already won an award at the American Hartley-Merrill international screenwriting competition. But loud voices in the Russian press have also expressed outrage at the breaking of a taboo, accusing Uchitel of muckraking disrespect to the writer. A sneering review in the liberal daily newspaper Segodnya concludes that His Wife's Diary is the inevitable first step down a slippery slope which will see the private lives of the nation's creative heroes recycled as soap operas. "Pushkin, Dostoyevsky and Tchaikovsky are next in the queue," writes critic Victoria Nikiforova. "They are being transformed from classical writers into pop stars." Another critic warns: "Many will no doubt be shocked by the themes in this film."

Uchitel was bemused by their response, explaining: "The Finance Commission voted to turn it down – objecting to what they described as hanging out the dirty linen of a great man. They asked, "Was it really necessary to touch on this side of him? Did you have to drag out the details of his love life? Do viewers really need to see this?" I was astonished. I thought that era was long over. A lot of the people on the Commission – made up of film directors and scriptwriters as well as civil servants – have been working in the film ministry for 30 or 40 years, and their thinking was guided by an old Soviet mentality. There was a great tradition of Soviet biographical films, where if they mentioned the hero's private life at all, they would portray everything as wonderful. The committee saw Bunin as an icon who shouldn't be touched."

From a western perspective, it is indeed hard to see what the fuss was about. Far from being a tabloid expose, this is a sensitive account of the emotions that overwhelmed the writer in his last years, loosely based on documentary evidence from Bunin's memoirs and the diary kept by his wife, Vera, as a form of escapism. Bunin's Nobel prize in 1933, the onset of the second world war, unsettling reports from Stalin's new regime in the Soviet Union – all these are background events, overshadowed by the writer's infatuation with the young poet Galina Plotnikova (actually Galina Kuznetsova, whose name has been changed to spare the feelings of surviving relatives). She arrives as Bunin's student, but remains his lover until abandoning him for another woman, the singer Marga Kovtun. Meanwhile his wife is wooed by another emigre Russian writer.

After a French co-production deal fell through (mainly, Uchitel says, because it came with the bizarre condition that Omar Sharif should play the lead), the film was beautifully shot in the run-down seaside towns and villas of the Crimea, convincingly transformed into a pre-war Cote d'Azur. The film shows Bunin in his 60s and 70s, when he was writing his last volume of stories, Dark Alleys – all of which focus on love and most of which end unhappily. Published in Paris in 1946, the stories were dismissed by many of his readers as sordid accounts of sexual encounters.

Uchitel argues that far from providing his viewers with gratuitous sensationalism, he is offering them an insight into the experiences that inspired this work. "You need to show how someone lives, what kind of stresses they are experiencing, what kind of romantic drama they are caught up in. Only then do you begin to understand that the writer did not simply sit down at his desk and dream up these wonderful stories. Those old films that showed the writer as utterly happy, his life very tidy, were so stupid. You need to show that his creation only came about because of the life he was living."

Nevertheless, Uchitel clearly has some residual guilt about his treatment of Bunin. Both he and the actor Andrei Smirnov, who plays the lead role, plan to visit the writer's grave in France – to ask his forgiveness.