Medina Spirit, the controversial winner of the 2021 Kentucky Derby, collapsed and died following a workout at Santa Anita Park on Monday, according to California Horse Racing Board's Equine medical director Jeff Blea. 

"I spoke to the attending veterinarian, and when they got to him on the track he had already expired," Dr. Blea said in a statement. "Not sure where on the track it happened, but it was post wire.

"I will have them draw blood and pull hair and will try and get urine for testing. He'll go out to UC Davis in San Bernardino, for a full and comprehensive necropsy including toxicology, forensics and tissue sampling. We will take a close look at the heart to try and identify the cause of death."

According to The Daily Racing Form, Medina Spirit, a three-year-old, did not die from complications of any kind of leg injury. Trainer Bob Baffert was set to run the horse at the Grade 2 San Antonio on Dec. 26 at Santa Anita, which is why the horse was working out at the track, DRF reported.

Medina Spirit's Kentucky Derby win was one that clouded in controversy because the colt tested positive for betamethasone following the race. The Kentucky Horse Racing Commission hasn't held any hearings yet regarding the win and those would need to occur in order to disqualify Medina Spirit.

Medina Spirit had run four different races since winning the Kentucky Derby. The colt finished third in the Preakness Stakes and won the Shared Belief Stakes and the Grade 1 Awesome Again. Medina Spirit had five career first place finishes and career earnings totaling $3.5 million.

The Kentucky Derby winner is the 20th horse to die at Santa Anita just this year, according to CBS Los Angeles. Between December of 2018 and January of 2020, 42 horses died on the track at Santa Anita.