Aleksandar Hemon plumbs the depths of his experience for his novels, to the extent that he has difficulty knowing which memories belong to him, and which to his characters, he tells Susan McKay

'PLEASE EXCUSE THE pornography - it's all legal," quips Aleksandar Hemon as he unlocks the door of his hotel bedroom. He lifts the net curtain screening a drab view of concrete walls and blank windows. "There's the swimming pool," he says, and, yes, the concrete box full of rainwater on the flat roof below does look exactly like a miniature swimming pool. It's a glimpse of the imagination which makes Hemon's writing so exciting. The unsettling opening remark is dispelled.

Before we begin, he has some arrangements to make for dinner, a call to one friend in English, and one to another in Bosnian. Then he stretches out in the room's one armchair, bites into a green apple, and admits he is exhausted. He is only in Dublin for a day between a reading from his new book, The Lazarus Project, in London and another in Edinburgh. It is evening, already less than 12 hours before his next flight.

Hemon is from Sarajevo, in Bosnia, "one of the saddest cities in Europe". His writing has been described as a kind of "autobiographical fiction" and the lives of his protagonists often seem to share the fundamentals of his own. In 1992, he came to Chicago intending to stay for a couple of months - but then Serbian forces besieged Sarajevo and he was unable to return.

Vladimir Brik, the writer whose investigation of the history of Lazarus Averbach is tangled up in his own life story in The Lazarus Project, is similarly displaced. One morning, making coffee, he spots a can in his kitchen labelled Sadness. "A bolt of pain went through my intestines before I realised that it was not Sadness but Sardines. It was too late for recovery, for sadness was now the dark matter of the universe of still objects around me."

Hemon's father was from Ukraine, and he says he is connected with the "Central European melancholy" which also pervades the work of WG Sebald, whose influence Hemon gladly acknowledges. The Lazarus Project is illustrated by enigmatic and uncaptioned black and white photographs, and painful history makes its presence felt in disquieting ways in Hemon's work as in Sebald's. In one Hemon story, an elderly woman with dementia and a blurred number tattooed on her arm interrupts an already fraught American family dinner to demand: "Where's Bruno?"

Like Sebald, Hemon writes books that cannot easily be categorised. "I don't think of them as collections of stories or novels," he says. "This one I knew as 'the big book'. Categories are for the marketing department. I consider my books to be literature."

There are Slavic elements and socialist influences in his background, Hemon says. "There is something about Slavs and East European Jews. They have the same sensibility. It was best expressed by Nabokov who said of Chekhov that he wrote sad books for humorous people."

He visits friends in Sarajevo several times a year, and finds that after a few days, his jaw is numb from laughing. "People tell you the funniest jokes," he says. "It is about exhilaration and despair - the exhilaration comes from how you deal with the despair. If it never stops, it can be a form of hysteria."

His books are full of dark hilarity and surreal visual observations. One of the narrators of Nowhere Man describes the furniture he has to sell when his savings run out. It includes "a hobbly table with four chairs, inexplicably scarred, as if they had walked through fields of barbed wire". A horse's turds are "like dark deflated tennis balls". A gangster in Ukraine drives "a gigantic Toyota Cherokee, or Toyota Apache, or Toyota Some Other Exterminated People".

Brik comments that he had got tired of telling his stories of childhood and immigrant adventures to his wife, because of the American craving for "the truth and nothing but the truth - reality is the fastest American commodity".

Sarajevans, by contrast, "told stories ever aware that the listeners' attention might flag, so they exaggerated and embellished and sometimes lied to keep it up. You listened, rapt, ready to laugh, indifferent to doubt or implausibility." It was all about "the pleasure of being in the story".

Rora, the friend who accompanies Brik on his journey in search of the story of Averbach, is a teller of such tales, and is impatient with Brik's metaphysical angst. Hemon delights in his freedom as a writer. He admits that while Averbach, a Russian Jewish immigrant who was shot by the chief of police in Chicago in 1908, is a historical figure, some accounts give his first name as Harry. "The Harry Project?" Hemon shakes his head. "I don't think so." Imagination, he insists, is a necessary mode of engagement with the world.

Then again, Rora was in Sarajevo during the war, so his outrageous stories may just as well be true as not. In one of Hemon's stories, a child describes how his family ended up with his grandmother's dead body in their apartment, unable to bring it out for burial because to open the door was to risk being picked off by a sniper. Finally, the stink is too much, and they have to heave her body out of the window.

SPEAKING OF ANOTHER of his narrators, Pronek from the book Nowhere Man, Hemon says: "I can't remember which memories are Pronek's and which are mine. I start from a personal space and then I expand. I am every person and the furniture."

What happens to Rora when he and Brik finally reach Sarajevo is shocking and sad, even though the racy heroics he had embroidered around himself unravel in his sister's telling. She is a doctor in the city's hospital and has little time for fantasy. Bandaging up Brik's hand, after his botched foray into acting the hard man, she tells him: "You will need it, for writing." Bringing the dead back to life is a miraculous business.

Hemon's hotel room is white and smells pleasingly, if slightly overwhelmingly, of bath products. His hair is cropped, he is dressed in clean, casual clothes, and his large, dark eyes look out through severely fashionable glasses, which are well polished. In his books, dishes pile up in greasy water, food rots, cockroaches march about, people vomit, spill their urine on their trousers, fall into toilets, and decline, or do not have the opportunity, to wash. Why?

"It is a reasonable question," he replies. "When I arrived in America, I'd go to a party and everyone was happy. Then someone would ask me about myself and I hated responding. You had to explain over and over again, and it wasn't party talk. My discomfort often expressed in a sense of being stinking. The presence of death makes you aware of your body. Death stinks."

War, he says, is "indelible". Those who survive it have to learn to deal with it. It is a common symptom of trauma, as experienced, for example, by people who were held in Serbian detention camps, that they could not talk about it, he says. The Hemon figure stranded in America, watches the war obsessively on television - not there, not here, either.

"I had tourist English," Hemon says of those days. "I had my native language as a default. But once I knew I had to stay, tourist English was insufficient. It wasn't deep in my mind, connected with fantasies and memories." He began to read literature in English, underlining the words in Nabokov's Lolita he didn't know, and looking them up in the dictionary. He read newspapers and worked in the sort of low-paid jobs that immigrants get. "I canvassed for Greenpeace - I talked a lot," he says.

Within five years, he had written his first book, The Question of Bruno, in dazzlingly stylish English. It was immediately acclaimed, and the reviews for Nowhere Man and this new book have been ecstatic. One critic predicted a Nobel prize for Hemon, who has already won a MacArthur "genius grant". He is a regular contributor to Granta and to the New Yorker, in which James Wood described him as "a post modernist mugged by history".

HEMON WAS A journalist before the war, but not, he says, a good one. "Temperamentally, I'm not a journalist," he says, though many of his friends in Bosnia are, and he engages with world affairs. He was glad when Radovan Karadzic was arrested. "It was overdue," he says. "It would have been better at the height of his powers. He had become disposable." Ratko Mladic is still a potent figure, though. "The Serbian army would get pissed if he was captured, and they can't afford to piss the army."

There is no going back to Bosnia. "My life is in Chicago. My wife is American, and my daughter is American. In Bosnia, I'd have to be absorbed into trauma, poverty and corruption," he says. However, there are references in his books to the "idiot president" of the US and there is a domestic argument about the torture of Iraqis by US soldiers at Abu Ghraib.

"For the past eight years, I've been wanting to leave the US, but I don't know where to go. But if John McCain is elected, I think I'd have to. I can't live in a country that repeatedly makes the same mistakes," he says. His parents now live in Canada, his sister in London. "I was at a wedding in London recently, a friend from Sarajevo. I realised that the guests had come from Canada, Switzerland, Croatia, England . . . all over the world. If they lived in one place, I would try to live there."

...

The Lazarus Project is published by Picador, £14.99"There is something about Slavs and East European Jews. It was best expressed by Nabokov who said of Chekhov that he wrote sad books for humorous people