The winner of the Kentucky Derby, Medina Spirit, was stripped of his victory on Monday by state racing stewards.
The steroid that Medina Spirit tested positive for was legal in Kentucky but banned on race day.
Bob Baffert won his seventh Kentucky Derby with Medina Spirit, who finished half a length ahead of Mandaloun. Baffert was banned for two years after a positive test.
The Kentucky Horse Racing Commission made Medina Sprit the second horse in the 146-year history of the race to be disqualified for a banned substance, the first being Dancer's Image in 1968. The only other disqualification was in 2019.
Following the announcement by the racing stewards, the Kentucky Derby winner was declared by Churchill Downs. The owners of Mandaloun will get the winner's purse.
The racing commission fined Baffert and suspended him for 90 days.
Medina Spirit died of a heart attack less than a month after finishing second in the Breeders' Cup Classic at Del Mar.