PETER Liston, the man who prepared Black Caviar's $5million half-brother for the yearling sales, has described the death of the horse as a "racing tragedy".
Black Caviar's half-brother, known as Jimmy, was euthanised on Sunday after battling laminitis for two months.
Liston's Three Bridges Stud in Eddington was chosen by breeder Rick Jamieson to prepare the colt for the Sydney Easter Yearling Sales in April.
The son of Redoute's Choice out of Black Caviar's mother Helsinge sold for an Australian record $5m.
The purchaser was the ill-fated BC3 Thoroughbreds.
"It's a racing tragedy,'' Liston said.
"It's very sad for the breeder and for the people who purchased into the horse with the idea of having a racehorse and a stallion prospect.
"With the collapse of BCS as well, it's a hard time for people involved."
Liston said he expected Jimmy to be a star on the racetrack.
"He was a superstar horse,'' Liston said.
"Äll reports from when he was broken in were really positive.
"Ï went and saw him about three months ago and he'd grown into a magnificent horse. Everything was looking very positive.
"Unfortunately, we'll never know how good he would have been."
Two yearlings that were owned by BC3 - a filly by Fastnet Rock and a filly by Star Witness - have been in Three Bridges' care since the collapse of BC3.
Magic Millions repossessed the fillies and they will be sold at the January 8-14 sales on the Gold Coast.
"The fillies will be sold on an unreserved basis and they're both nice fillies,'' Liston said.
"The Fastnet Rock filly was originally bought for $260,000 by BC3 and I would think Magic Millions would recoup that price with her."
Three Bridges has a busy sales period ahead.
The stud has prepared nine yearlings for the Magic Millions sales, eight for the Sydney Classic sales and five in the Sydney Easter sales.
Three Bridges biggest crop is 29 for the Melbourne Premier Yearling Sales in March.
The sales will include the first progeny of Three Bridges' stallion Stryker - a son of Fastnet Rock.
Three Bridges will hold an Open Day on Monday, February 17, where it will parade its yearlings for the autumn sales.