The claim that Adolf Hitler escaped his Berlin bunker to live incognito in Argentina first gained currency in 1945, when Joseph Stalin spoke of it.
Since then the idea has resurfaced occasionally, with alleged photographic and documentary evidence.
Now the theory that the German dictator followed his fellow Nazis Adolf Eichmann and Josef Mengele to South America is at the centre of a fresh row.
The authors of the 2011 book Grey Wolf: The Escape of Adolf Hitler, which was made into a documentary film this year, have been accused of plagiarism by an Argentine journalist, Abel Basti.
Grey Wolf, published by Sterling Publishing, challenged the accepted view that Hitler shot himself in his Berlin bunker on April 30, 1945 and that Eva Braun also committed suicide by taking cyanide. Arguing that American intelligence turned a blind eye to Hitler's escape in return for access to Nazi war technology, Gerrard Williams and Simon Dunstan set out the case that the Fuhrer and Braun made a home in the Andes foothills and had two daughters.
Hitler, they claim, escaped punishment and lived in Patagonia until his death in 1962, aged 73.
The publisher billed the book as the result "of five years of travelling and interviewing eyewitnesses and piecing together a mountain of evidence".
Basti alleges that Williams and Dunstan used evidence he had spent years putting together. Williams, a British TV journalist, and his co-author firmly deny the claim.
"Basti did in no way invent the idea of Hitler being alive in Argentina," Williams said. "Books on the subject existed as far back as 1953."
Williams travelled in 2007 to Argentina where, he acknowledges, he received help from Basti, along with other researchers and translators. Basti claims that on seeing the book and hearing of the new film he realised that work he had handed over to Williams for use on an earlier documentary had been plagiarised.
Basti says he signed a contract conferring all rights to his work to Williams' company in return for substantial payments to come.
Filming began in September 2008, but was cut short when financiers pulled out due to the worldwide financial crisis. Basti claims his contract was terminated and so asked for his research to be returned but says nothing was sent back.
The claims about Hitler's life in Argentina have been ridiculed by historian Guy Walters, who pronounced them "2000% rubbish" when the book came out.
"There's no substance to it at all. It appeals to the deluded fantasies of conspiracy theorists and has no place whatsoever in historical research."