Medina Spirit has been stripped of last year's Kentucky Derby victory and trainer Bob Baffert suspended and fined over the colt's positive drug test last May, the Kentucky Horse Racing Commission (KHRC) said Monday.

The Amr Zedan-owned colt -- who died suddenly during a workout in California in December -- tested positive for traces of betamethasone, an anti-inflammatory steroid medication that is legal in US racing but cannot be used within 14 days of competition.

Churchill Downs racetrack had banned Baffert, who denied all wrongdoing, for two years while the KHRC launched its investigation.

In a statement issued Monday, the KHRC said Medina Spirit had been disqualified "and all purse money forfeited."

It's just the third time in the 146-year history of the Kentucky Derby that a winner has been disqualified.

The move makes Mandaloun the winner of the 2021 Kentucky Derby, although there will be no refunds or payouts for anyone who bet on the horse, officials said.

The last time a horse was disqualified for a prohibited substance in the Kentucky Derby was in 1968, when Dancer's Image was removed as the winner and Forward Pass was awarded the victory in a case that too four years to resolve.

In 2019, Maximum Security was disqualified because of interference during the race.

Medina Spirit, ridden by jockey John Velazquez, crosses the finish line to win the 147th running of the Kentucky Derby ahead of Mandaloun, ridden by Florent Geroux. Kentucky racing officials have stripped Medina Spirit of the victory over a positive test
Medina Spirit, ridden by jockey John Velazquez, crosses the finish line to win the 147th running of the Kentucky Derby ahead of Mandaloun, ridden by Florent Geroux. Kentucky racing officials have stripped Medina Spirit of the victory over a positive test for a medication banned on race-day. GETTY IMAGES NORTH AMERICA via AFP / Rob Carr

Baffert was suspended 90 days and fined $7,500. The winner's purse of $1.86 million will have to be returned and will be awarded to Mandaloun's owners.

However, Baffert's lawyer Craig Robertson told the Daily Racing Form that Medina Spirit's camp would file "an immediate appeal."

Baffert has said the medication found in Medina Spirit's system was the result of a legal application of a topical ointment, rather than an injection.

The colt was the fifth horse trained by Baffert in 12 months to fail a drugs test.

He was already barred from entering horses in this year's Kentucky Derby and the 2023 edition, and has also been banned by New York racing authorities from entering horses at Belmont, Saratoga and Aqueduct race tracks.

Medina spirit collapsed and died at the end of a workout at Santa Anita Park on December 6.

This month the California Horse Racing Board released the report of a necropsy on the colt that showed no definitive cause of death.

The post-mortem examination, required for any horse that dies suddenly at a California racing facility, included toxicology tests that found anti-ulcer medication and the diuretic Lasix but "no other drugs, heavy metals or toxicants" in blood or urine samples.