(CNN) The Kentucky Horse Racing Commission announced Monday that Medina Spirit's victory at the 2021 Kentucky Derby has been disqualified.
The horse failed a drug test after crossing the finish line first at the Derby.
Medina Spirit died in December. The thoroughbred was finishing a workout when he collapsed near the finish line at the Santa Anita Park racetrack.
The KHRC also announced a 90-day suspension for Hall of Fame trainer Bob Baffert, who trained Medina Spirit, and fined him $7,500. Baffert said he plans to appeal the decision.
"I am very disappointed in the ruling," Baffert said in a statement provided by his spokesperson to CNN. "It runs contrary to the scientifically proven facts in this case and the rules of the Kentucky Horse Racing Commission. We will be filing an immediate appeal."
The commission said the winner's purse of $1.86 million must be returned.
Churchill Downs, where the famed race takes place, said Mandaloun is now the winner of the 147th running of the Kentucky Derby.
"Today Churchill Downs recognizes Mandaloun as the winner of the 147th running of the Kentucky Derby and extends our congratulations to owner/breeder Juddmonte, trainer Brad Cox and jockey Florent Geroux," Churchill Downs said in a statement Monday.
"Winning the Kentucky Derby is one of the most exciting achievements in sports and we look forward to celebrating Mandaloun on a future date in a way that is fitting of this rare distinction."