A handwritten notebook of tonics used by the trainer of legendary racehorse Phar Lap, which may shed new light on his death from poisoning, has sold at auction for $37,000.
The 82-page notebook, which belonged to Phar Lap's trainer Harry Telford, provides the first written proof of the tonics and ointments he used on racehorses.
Twenty-eight of the homeopathic recipes in the notebook were written in Telford's hand, with two others added by his track-work jockey, Ernie Fellows, auctioneer Charles Leski of Charles Leski Auctions in Melbourne said.
Ingredients of some of them include arsenic, strychnine, belladonna, cocaine and caffeine - poisonous in large amounts but used to give horses an extra edge in the days before swabbing.
Phar Lap won 37 of his 51 starts, including 14 wins in a row and the 1930 Melbourne Cup.
He went to the United States in 1932, accompanied by his strapper and stand-in trainer Tom Woodcock.
The big red won his first race on US soil but died at the Menlo Park racetrack in California on April 5.
Conspiracy theories flourished, including suggestions gangsters killed off the champion Australian-owned, New Zealand-bred gelding.
But on his deathbed in 1985, Woodcock admitted Phar Lap might have died from ingesting too much of one of his tonics.
Mr Leski said the notebook was sold among a range of sporting memorabilia.
It was purchased by Museum Victoria, which has displayed Phar Lap's hide and other memorabilia since 1933.
Four bidders drove the price from the minimum bid of $7,500, with the final price well exceeding the estimate of $10,000 to $20,000.
"It's the first time that we have had, in writing, confirmation that caffeine, cocaine, belladonna, strychnine - all of them we think of as poisons - were actually used by Harry Telford in the maintenance of his horses," Mr Leski told AAP.
"In strictly measured doses and mixed in with other feed, presumably these served the purpose of being a stimulant and didn't adversely affect the horses.
"But if Phar Lap had been unwell in the trip over to America or if he had been in the hands of more than one person in the US, it's possible the dosage wasn't strictly adhered to and it would appear he overdoses on a concoction that was considered good for him.
"This was considered quite normal at the time."