Kentucky Derby winner Medina Spirit faces disqualification after a second drugs test came back positive for a prohibited substance.
The lawyer for Medina Spirit's trainer, Bob Baffert, confirmed on Wednesday that a split-sample came back positive for the presence of the steroid betamethasone.
Attorney Craig Robertson said the test showed 25 picograms of the steroid, after 21 were found initially. Even a trace amount of betamethasone is prohibited on race day in Kentucky and considered a violation.
Robertson said additional testing is being conducted to try to trace the source of the drug to an ointment to treat a skin infection and not an injection.
"At the end of the day, we anticipate this case to be about the treatment of Medina Spirits skin rash with Otomax", he said. "We will have nothing further to say until the additional testing is complete."
A spokeswoman for the Kentucky Horse Racing Commission declined to comment, citing the ongoing investigation. Sherelle Roberts-Pierre said the commission values fairness and transparency and will provide information to the media and public at the close of an investigation.
If Medina Spirit is disqualified, Mandaloun would be elevated as the winner of the Kentucky Derby.
Baffert is currently suspended by New York and not allowed to enter any horses in the Belmont Stakes pending the Derby investigation.
After the initial positive test, Baffert insisted he was innocent of any wrongdoing, describing the findings as "a gut punch".