Barney Curley, the mastermind behind some of racing's most famous betting coups and successful former trainer, has died at the age of 81.
Northern Ireland-born Curley's skirmishes with the bookmakers and dramatic gambles became the stuff of legend, in particular that involving Yellow Sam in June 1975
He was also famed for the work he did for his charity, Direct Aid For Africa, which he founded in 1996.
Newmarket-based John Butler was assistant to Curley for a number of years and paid tribute to his former boss, who had battled against cancer.
"He died very peacefully on the stud (in Newmarket) on Sunday. It was pretty sudden, he got poorly very quickly," he said.
"I came over to England (from Ireland) 18 to 20 years ago and worked for him for seven or eight years. It's a sad day."
In 2007 Curley - who won the Imperial Cup at Sandown in 2000 with Magic Combination - announced he would be dedicating more time to his charity, one which attracted a £2.5m donation from Sheikh Mohammed.
Butler said: "His charity was his main thing the last 10 or 15 years, it was always the charity no matter what.
"Every day it was his charity. On several occasions we emptied furniture out of schools and filled containers and he always went away and the charity came first. The horses were there, but the charity was a massive thing.
"You could spend all night talking about him. He was very good to me, he was just one of those people."
"His racing tales were legendary but the work he put in to help the poor in Africa was absolutely outstanding."
Curley, who had his last runners in 2012, was instrumental in the early careers of jockeys such as Frankie Dettori and Jamie Spencer.
Butler added: "He was good to Spencer and (Tom) Queally and Shane Kelly, Frankie - I think Frankie went to see him every day for the last two or three weeks."
Adding his tribute, multiple champion National Hunt jockey Anthony McCoy wrote on Twitter: "Very sad to hear that Barney Curley has passed away.
"Feel lucky to have enjoyed his company - a man with well-founded legendary status as a trainer/gambler, but one who also raised lots for the charity Direct Aid For Africa. RIP."
Gold Cup and Grand National-winning trainer Jonjo O'Neill tweeted: "Very sorry to hear the sad news that Barney Curley has died.
"One of racing's great characters. RIP."
Presenter Derek Thompson said on his Twitter page: "So sad to hear of the passing of Barney Curley at the age of 81.
"His racing tales were legendary but the work he put in to help the poor in Africa was absolutely outstanding. RIP Barney."