NEW YORK (AFP) - A hidden manuscript written by British mathematician and codebreaker Alan Turing at Bletchley Park is to go on auction in New York in April, Bonhams said Tuesday.
The extraordinary document from 1942, when Turing was working to crack the Nazi's Enigma Code, is expected to fetch at least US$1 million (S$1.3 million), the auction house said.
The sale is expected to capitalise on enormous interest in Turing's life and work generated by Hollywood film The Imitation Game, which has been nominated for eight Academy Awards for next month's Oscars ceremony.
Turing was a computer scientist, philosopher and cryptologist ahead of his time and the film coincides with the 60th anniversary of his death.
Bonhams said the 56-page manuscript is "almost certainly the only extensive autograph manuscript by Turing in existence, and has never been seen in public".
The document deals with the foundations of mathematical notation and computer science, and offers "remarkable insight into the thought process of a genius", it said.
Bonhams said the manuscript is expected to sell for at least seven figures at the sale on April 13, and that a portion of the proceeds will be donated to charity.
British actor Benedict Cumberbatch, the star of The Imitation Game and nominated for an Oscar for his portrayal of Turing, said the prospect of being able to hold one of his manuscripts was "thrilling".
"Alan Turing was a war hero, who broke the Enigma code helping to bring an end to World War II, the father of modern computing science, and a gay icon who lived in a time of intolerance and tragically committed suicide as a result," Bonhams quoted him as saying.
"His impact on our everyday lives is enormous, and the thought of being able to hold a manuscript that was written by him is thrilling."
Turing was prosecuted for homosexuality in 1952 when it was a crime in Britain, despite the fact that he had played a crucial role in deciphering German codes that experts say accelerated the fall of Adolf Hitler.
Forced to undergo chemical castration, Turing killed himself at the age of 41.
He was officially pardoned only in 2013 by Queen Elizabeth II, six decades after his tragic death.
The document is contained in a simple notebook bought from a stationers in the English university city of Cambridge, where Turing was a fellow at King's College.
It was among papers left by Turing after his death in 1954 to friend and fellow mathematician, Robin Gandy.
In blank pages of the notebook, Gandy wrote a journal in which he called Turing a "dead father figure".
Bonhams said the document remained hidden among Gandy's personal effects until his death.
Andrew Hodges, who wrote the biography that inspired The Imitation Game said Turing was "parsimonious with his words and everything from his pen has special value.
"This notebook shines extra light on how, even when he was enmeshed in great world events, he remained committed to free-thinking work in pure mathematics."