Arrowfield Stud's talented blueblood Miracle Of Love died of a suspected heart attack during a barrier trial at Scone on Wednesday.
Trained by Paul Messara and Leah Gavranich, the 3-year-old daughter of Dundeel and Miss Finland started three times.
A third on debut in the Listed Woodlands Stud Stakes at Scone last May, Miracle Of Love broke her maiden a fortnight later at Doomben.
Solidly backed in the Group 1 JJ Atkins Stakes at Eagle Farm on June 10, Miracle Of Love clocked in second behind King Colorado and has not started since.
A distraught John Messara told Racenet it took some time to process the tragic news.
"Paul rang, it was the call I'd been waiting for, and I thought he was going to tell me how well the filly trialled,'' Messara told Racenet.
"But when he told me what happened, I said: 'You are pulling my leg'. I couldn't believe it.
"I feel so sorry for Paul; he has put so much work into this filly. She was an outstanding filly; we thought she had Group 1 potential.
"We couldn't wait to get her back to the races, and then this happened. This game is a great leveller.''
Miracle Of Love is a half-sister to Group 1 MRC One Thousand Guineas heroine Stay With Me (Street Cry), the dam of dual Listed stakes-winner Waltz On By (I Am Invincible).
The 5-time Group 1 winner, Miss Finland, has a 2-year-old colt by Castelvecchio named Castel Nuovo in the stable of Richard Litt. Ottavio Galletta had purchased him for $280,000 from the Arrowfield Stud draft at the Inglis Australian Easter Yearling Sale.
Miss Finland's final foal is a yearling sister to Miracle Of Love.