Murray Sayle: Journalist and adventurer celebrated for his investigation into the 1945 atom-bombings

A big, barrel-chested, hatchet-faced man with a broken nose and a sardonic smile, Murray Sayle was one of the most brilliant journalists of his generation and at his frequent best demonstrated a passion for his craft both as a tool for establishing truth and as a vehicle of literary delight. All you needed to be a journalist, he liked to quip, was a little literary ability and rat-like cunning. But behind the Aussie cynicism lay a belief in the value of his profession when practiced with total commitment which was an inspiration to many who crossed his path. Few journalists took their investigative work more seriously, or placed more onerous demands on their chosen editors.

Murray was an outstanding member of the great Australian literary diaspora that hit London from the early-1950s onwards and included such stars as Germaine Greer, Richard Neville, Philip Knightley and Clive James. Like them he possessed a protean energy and a refusal to acknowledge conventional boundaries or limitations which left their British competitors gasping.

The son of a railway executive, born in New South Wales in 1926, he studied psychology at the University of Sydney but became so absorbed in his work for the student magazine, Honi Soit, that he missed 90 per cent of his lectures and was excluded from taking his finals. He made up for it some 64 years later when the university awarded him an honorary doctorate.

On leaving university he was quickly taken up by the Sydney media, working for the Sydney Daily Telegraph and the Daily Mirror and national radio. Then in 1952 he left for London where he was hired by The People, at the time a vigorous and very profitable Sunday scandal sheet. Working alongside the paper's legendary crime reporter Duncan Webb he picked up, or possibly invented, the catchphrase, "I made an excuse and left."

But his first marriage was breaking up and in 1956 he left The People, journalism and London, beginning an improbable interlude selling encyclopaedias in Germany and writing a novel based on his Fleet Street experiences entitled A Crooked Sixpence. It might have made his name had not a friend called Michael Alexander, who was broke at the time and hoping for an easy pay-out, complained to the publisher that one of the novel's characters was based on himself, threatening to sue. Instead of paying him to shut up the publisher pulped all copies and the book disappeared without trace. It was recently re-published and acclaimed as a Fleet Street classic.

By the mid-'60s he was back in London and doing newsroom shifts at the Sunday Times, where his tireless digging for facts, his vigorous, flinty style and his ironical wit soon got him noticed. Harold Evans, the legendary editor of the Sunday Times, made him the paper's chief foreign fireman, with license to roam the world's hot spots, reporting the Vietnam, Indo-Pakistan and Six-Day wars among other big stories, and being awarded Journalist of the Year for his Vietnam reports. But Murray was never satisfied in running with the pack, and his most memorable and extraordinary dispatches were all done solo: using a light airplane to track the round-the-world yachtsman Francis Chichester as he sailed around Cape Horn, then, on the same expedition, searching for (though not actually locating) Che Guevara in Bolivia, becoming the first journalist to report that the guerrilla leader had left Cuba for South America.

Sayle also exploited his cachet as one of Harry Evans's "licensed eccentrics" to climb Mount Everest and sail single-handed across the Atlantic, among other macho exploits on the margins of serious journalism. But as a veteran war reporter his obsession, lasting for the rest of his working life, was with official violence and the lies with which it becomes encrusted to justify or obfuscate it.

His investigation into Bloody Sunday in 1972 led him to the conclusion, vindicated in the government's admission earlier this year, that the British paratroopers had not been fired on by those they shot, killing 13. But when the Sunday Times spiked his report, with its claim that the killings had been planned in advance, he resigned, and his mercurially brilliant London career was over.

With his second wife Jenny Murray he moved east, first to Hong Kong and then, in 1975, to Japan, which was to become the family's home for nearly 30 years. They settled in the remote and entirely obscure village of Aikawa, in Kanagawa Prefecture, where they lived in a traditional wooden house, freezing cold in winter, from which Murray would descend on the Foreign Correspondents' Club in central Tokyo at intervals to hold court among his peers. But despite the apparent seclusion, these were years of great productivity: he had arrived in Japan at the most pregnant moment of its postwar history, and was to witness and record its long years of boom, its precipitous slump and slow recovery in witty, erudite and immensely long pieces for The Independent Magazine, the New Yorker and the New York Review of Books, among others. His obsession with official cover-ups remained a constant: he wrote copiously about Tiananmen Square and the disappearance of the Korean airliner KAL007, reaching controversial conclusions backed by exhaustive research.

His crowning journalistic achievement, for which the New Yorker cleared out an entire issue in 1995, was entitled "Did the Bomb End the War?" and concerned one of those facts that "everybody knows" but which, in his view, was not actually true: the notion that it was the atom-bombing of Hiroshima and Nagasaki that persuaded the Japanese to surrender. Sayle advanced a powerful case for believing that actually it was the Soviet invasion of Manchuria, with the implicit danger that they would then invade Hokkaido and force a division of Japan like that of Korea, which was actually the crucial event.

The Sayle family moved back to Australia in 2004 when Murray was diagnosed with Parkinson's disease. His honorary doctorate described him as "a witness to history in the classic tradition of journalism and foreign correspondence." That a career such as his is unthinkable today, with or without a video camera to hand, is a measure of how much more challenging the profession has become.

Murray Sayle, journalist and novelist: born Sydney, Australia 1 January 1926; married firstly Maria Theresa von Stockert (marriage dissolved), secondly Jenny Murray (three children); died Sydney 18 September 2010.