Lexington, Kentucky - Medina Spirit failed a post-race drug test just a week after winning the Kentucky Derby, Hall of Fame trainer Bob Baffert announced Sunday outside his barn at Churchill Downs.

Former President Donald Trump waded into the controversy on Sunday with a post on his blog, calling the horse "a junky" and complaining that the "whole world is laughing at us."

Baffert, who won his seventh Kentucky Derby with the colt on May 1, said that the horse was found to have 21 picograms of the steroid betamethasone, double the legal threshold in Kentucky racing, in a post-race sample.

"I was totally shocked when I heard this news," Baffert said during a news conference.

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"I’m still trying to absorb it. I am the most scrutinized trainer. And I am OK with that. The last thing I want to do is something that would jeopardize the greatest sport."

But Baffert steadfastly denied any wrongdoing.

"Yesterday I got the biggest gut punch in racing for something that I didn’t do," he said. "It’s disturbing. It’s an injustice to the horse."

Baffert has been suspended by Churchill Downs "given the seriousness of the alleged offence."

Betamethasone, a corticosteroid injected into joints to help with pain and swelling, was also found in Baffert's horse Gamine last year after the Kentucky Oaks race. Baffert was fined $1,500, Gamine was disqualified, and her owners were denied the purse for winning third place.

Baffert’s horses have failed 30 drug tests over the past four decades, including five in just over a year, according to a tally by The New York Times.

According to Kentucky Horse Racing Commission regulations, a second positive test is required before a horse can be disqualified.

Baffert said he still plans for Medina Spirit to race at Saturday’s Preakness Stakes.