Only a few months before his acclaimed final novel, Lost Voices, was published last October, he was diagnosed with cancer.

Koch once described writing as an absurd occupation. ‘‘All writers are obviously neurotic ... For various reasons, writers retreat into an imaginary world because they find ordinary life rather difficult or boring or both.’’

His published life began with a poem in The Bulletin but he quickly realised he wanted to devote himself to fiction: ‘‘Poetry was the first step and from the age of 18 there was nothing else I wanted to do.’’

His first novel, The Boys in the Island, was published in 1958 and good reviews encouraged him to carry on with his writing while he worked for the ABC. He committed to full-time writing in 1972.

Koch is probably best known for The Year of Living Dangerously, which was published in 1978 and subsequently filmed by Peter Weir with Mel Gibson as the Australian journalist embroiled in Indonesian political turmoil.

But he won the Miles Franklin in 1985 for The Doubleman, about which British novelist Graham Greene wrote: ‘‘Koch has an extraordinary power of evoking place, and I feel now that Tasmania is part of my memory.’’

He won again in 1996 for Highways to a War. If he was frequently associated with Asia, his heart lay in Tasmania. He lived much of his life in Asia and Sydney but returned permanently to his home state in 2004.

HarperCollins publishing director Shona Martyn said she was very proud to have published Lost Voices, his eighth novel, and to have brought all his earlier novels back into print. ‘‘Even last week he was talking to editors about punctuation. He had a great commitment to his work.’’

2012 interview with Koch

THE book a man produces at 80 might be seen as a map of his life's deepest concerns, and so it is with Christopher Koch's Lost Voices. The novel, like the man, has returned to his native Tasmania and it began, he says, with his ''interest in the idea that the past resonates off the future. I've done it before in Out of Ireland and Highways to a War but this time I wanted it to be within a family.

''I wanted to look back from a distance at my childhood. This is probably the least autobiographical book I've written in terms of the characters but I've tried to create a sense of what it was like here in the 1940s. At my age you realise you are living in a different world from the one you grew up in.''

Koch is speaking to me by phone, even though we are both in Tasmania - he's at home in the historic village of Richmond and I'm at a hotel in Hobart, where his publisher has gathered a crowd to celebrate the launch of Lost Voices. It wasn't meant to be this way but Koch recently had surgery and is still too unwell to attend his own party. Instead, he submits generously to a day of telephone interviews.

There's an elegiac tone to Lost Voices, a hefty double narrative that begins and ends as a fictional memoir of Hugh Dixon, an aspiring artist in the 1950s, and in the middle looks back a century to the story of Hugh's great-grandfather, Martin Dixon, the bored son of a wealthy farming family who ran away to join a utopian community of bushrangers. The link between them is Martin's grandson, Walter, an elderly lawyer who lives alone in the family farmhouse and, through Hugh, seems to consummate his father's dreams and make amends for his regrets.

Koch has achieved the two-part structure and past-present resonance he tried with Highways to a War and Out of Ireland, which were meant to be one volume titled Beware of the Past but grew too large.

In Lost Voices, ''every character in the 19th century has a counterpart in the 20th century''. In life, Koch says, ''things that happen in the past have counterparts in the present. We have ancestral memories - it sounds a bit far out but so many Australians go to Europe to the places of their ancestors and recognise those places.'' Koch himself, who had German, Swiss, English and Irish forebears, remembers travelling through Switzerland and feeling that he'd been in a particular valley before.

He also cites scientific research into animal memory. ''Chickens run from the shadow of the hawk and they have never seen a hawk; certain memory circuits are inherited from the mother. If animals have this, why should it not be stronger in humans?''

Like his character Hugh, Koch at 17 did a short stint as a press artist with The Mercury in Hobart. But he says, ''I was completely devoted to reading and books from the age of seven. It took until I was 18 to have the confidence to write poetry.''

An English teacher fostered his love of poetry and a first job in a bookshop at 15 introduced him to the classics.

His first poems were published in The Bulletin while he was at school and he began a novel at university. After graduation he went to the mainland to join the ABC as a cadet journalist and from there to India and London, where he took jobs as a waiter and a school teacher while finishing the novel. Before returning to Australia he left it with an agent - later the novelist Paul Scott - who sold it to a British publisher.

''Australians didn't publish in England, except White and Stow, who got started about the same time I did, so it was quite a big thing,'' he says.

Good reviews in London for The Boys in the Island (1958) helped launch his career. Koch worked for a decade as a radio producer for the ABC and left to write full-time in 1972. Several of his books are set in Asia, where he lived for a time; most famously The Year of Living Dangerously (1978), based partly on his brother's experiences and filmed by Peter Weir with Mel Gibson as the Australian correspondent caught up in the 1965 overthrow of Indonesia's President Sukarno.

Koch has returned to Tasmania several times in person and fiction, drawn mostly by the landscape. There were six years in Launceston in the '70s with his first wife and son, and another four years in the early '90s. Graham Greene wrote of The Doubleman (1985): ''Koch has an extraordinary power of evoking place, and I feel now that Tasmania is part of my memory.'' That novel and Highways to a War (1995), set mainly in Cambodia, won him Miles Franklin awards, and in 1995 he was made an Officer of the Order of Australia.

After many years in Sydney, Koch and his second wife, Robin, decided eight years ago that even leafy north shore Wahroonga was oppressive. There was, too, ''economic necessity. There's no pension for old writers.'' They moved to a modern house on an acre outside Georgian Richmond, where he has planted more than 40 trees and looks out to the river and hills he describes intimately in Lost Voices.

Beyond the physical there is also a metaphysical and moral landscape, another of Koch's abiding interests. The utopia in the mountains is the fictional vision of Lucas Wilson, a charismatic and disillusioned former soldier who had been transported for punching an officer. In Van Diemen's Land he believes he can create a Rousseauian life that turns from the ills of civilisation back to nature and self-sufficiency. However, the men live by raiding farms and Wilson keeps order with a gun.

''It's an idea I believe doesn't work,'' Koch says, likening Wilson's utopia to 20th-century communism and hippie communes. At university Koch embraced anarchism, wanting the abolition of money and the state for a society that shared everything. ''But it is inevitable that it ends up being a dictatorship. Anarchism was never put into practice except in Spain and the communists destroyed them … I gave it up by the time I was about 23.''

As a Catholic - ''not a conventional Catholic'' - Koch believes in the existence of evil, represented in the novel by two characters - escaped convict Roy Griffin and commercial artist Max Fell. ''I think it's quite rare,'' he says. ''Major criminals … are not evil; they're human beings gone wrong for a variety of reasons. But it's difficult for people who don't believe in evil to explain Charles Manson or the Moors murders.''

On the other hand, he says, ''I don't believe novels should carry an obvious message. I don't want to write characters you can immediately say are good or bad; as in life, most people are a mixture.'' He admires and tries to emulate Dostoyevsky's ability to create sympathy for even the most degenerate characters. Lost Voices is dedicated to Frank Devine, the former editor of and a columnist for The Australian and a Catholic who was one of Koch's conservative inner circle until his death three years ago.

''He was extremely loveable and a great friend of my work,'' Koch says. ''I went to Sydney when he was in the hospice and he was still full of bonhomie. I read him a chapter from the book and he really liked it.''

Another close friend, poet Jamie Grant, launches Lost Voices at Hobart's Henry Jones Art Hotel the evening after my interview with Koch. He makes the claim that Koch is ''Australia's finest living writer of fiction'', even if Patrick White were still alive, on grounds of plot, structure, characterisation, dialogue, depth of content and prose style. ''Each of these elements is polished to the highest degree … No one matches Koch for elegance, clarity and rhythmic effect.''

Grant is married to Koch's agent, Margaret Connolly, and edits his books. His only influence on Lost Voices, he says half-jokingly, was to persuade Koch to remove the phrase ''two-humped Mount Direction'', which has appeared before in his descriptions of Tasmania.

Koch is sometimes described as a traditional or even old-fashioned writer, though he is more idiosyncratic than that. He has been a public critic of deconstructionism, which he says ''has had its day''.

Still, he says, ''I think the novel is in a sort of decline, with some exceptions. Cormac McCarthy is extraordinary - one of very few who deal with plot and character. Richard Ford writes very well. There's a tendency in a lot of contemporary novelists to sensationalise - they open with a weird or contentious scene and you know it's done for effect.''

After a long and celebrated career, is he satisfied with his achievements? ''We would all like to be more successful than we are. I would like to be a major figure in America and Europe, but that's the situation of the Australian writer.''

Koch's new publisher, HarperCollins, is bringing all his books back into print in handsome new editions - a compliment to any author. And he will keep writing, though, as usual, he has no inkling of what the next book will be.

''It's all I know how to do,'' he says. ''I wouldn't know what to do if I didn't write. As Kenneth Slessor said, writing is a pleasure out of hell.''

■Lost Voices is published by HarperCollins at $32.99. Susan Wyndham travelled to Hobart as a guest of the publisher.