Scientists have proven once and for all that champion New Zealand-born racehorse Phar Lap died from a lethal dose of arsenic.
The Timaru-born Phar Lap - sold to Australians at the Trentham yearling sales - won 37 of his 51 starts, after starting his career unimpressively.
That included 14 wins in a row and the 1930 Melbourne Cup, before his death in April 5 1932 at Menlo Park racetrack in California.
Mystery has always surrounded the tragic death of the champion gelding during the Depression years when he was at the height of his powers, with arsenic poisoning long suspected.
Two researchers - Dr Ivan Kempson from the University of South Australia and Dermot Henry, manager of Natural Science Collections at Museum Victoria - have now confirmed those suspicions.
But they can't answer the other burning question - who gave Big Red the arsenic? Dr Kempson took hairs from Phar Lap's mane and analysed them at the Advanced Photon Source Synchrotron in Chicago and found it was possible to distinguish between arsenic ingested and arsenic used in the taxidermy process.
He found that in the 40 hours leading up to Phar Lap's death in a California stable in April 1932 the horse had ingested a massive dose of arsenic.
"We can't speculate where the arsenic came from, but it was easily accessible at the time," Mr Henry said.
History suggests it was probably strapper Tommy Woodcock who may have mistakenly put too much arsenic in one of his tonics for his beloved Phar Lap.
Woodcock was acting as trainer for the first time on the trip to the US, with regular handler Harry Telford remaining at home to look after the rest of his stable.
Museum Victoria recently obtained Telford's handwritten notebook of homeopathic recipes used to stimulate horses.
The museum bought it at auction for $38,000 in April and it listed ingredients involving arsenic and strychnine used in tonics and ointments.
Racehorse veterinarian David McKellar told the ABC that over a period arsenic built up to levels that would become more and more toxic to the body.
"Obviously once the threshold of tolerance was exceeded then you would get the onset of the clinical symptoms." Phar Lap won the Agua Caliente Handicap in Mexico on March 20 1932, at that time the richest race in the world.
Two weeks later, he died in Woodcock's arms after making a 1000km float trip back to California.
On his deathbed in 1985, Woodcock admitted the horse might have died from ingesting too much of one of the tonics.
Henry said the researchers had found suitable taxidermied horses to compare the behaviour of the arsenic used in the preservation process with ingested arsenic.
"Our findings are underscored by the results of Phar Lap's autopsy, which are consistent with other published cases we have found of horses dying from arsenic poisoning." Phar Lap's death fuelled many conspiracy theories, among them was it was a result of a plot by US gangsters to get rid him because he was too successful.
After his demise, Australia and New Zealand went into mourning. He was the hero of the Depression era, a shining hope when there was poverty and desperation among the masses.
He was widely referred to as Australian, to the extent that one of his great rivals, his half-brother Nightmarch, was often described Australian writers as "the Kiwi".
With the advent of newsreels, Phar Lap became one of Australia's greatest sporting heroes as his name and deeds spread far beyond the confines of the racetrack.
Museum curator Michael Reason, who successfully bid for Telford's notebooks, doubted there was any more Phar Lap memorabilia floating around.
He said the 1930 Melbourne Cup was probably melted down by Telford and sold for its metal value.
"There was no sporting memorabilia market back then and the temptation would have been to melt it down and sell it," Mr Reason said.
Phar Lap's Cox Plate cup was recently purchased by Makybe Diva owner Tony Santic for around $400,000.
If the 1930 Melbourne Cup had survived it would be worth more than $1 million, Mr Reason said.
Phar Lap's skeleton is on exhibit in Wellington at the Museum of New Zealand and his heart is at the National Museum in Canberra.
His stuffed body -- his hide mounted on a shell of moulded materials -- is one of Melbourne Museum's most popular exhibits.
