LOS ANGELES • Legendary trainer Bob Baffert on Thursday denied doping last year's Triple Crown winner Justify after it emerged the horse failed a drug test before last year's Kentucky Derby.

US racing was rocked on Wednesday after the New York Times revealed that Baffert's Justify had tested positive for the banned substance scopolamine weeks before winning the first leg of the Triple Crown at Churchill Downs.

In a statement on Thursday, Baffert said the scopolamine entered Justify's system through contaminated feed.

"I unequivocally reject any implication that scopolamine was ever intentionally administered to Justify, or any of my horses," he said in a statement.

"Test results indicating trace amounts of the drug were undoubtedly the result of environmental contamination caused by the presence of jimson weed in feed, a naturally growing substance in areas where hay and straw are produced in California.

"In addition, I had no input into, or influence on, the decisions made by the California Horse Racing Board (CHRB)."

Chuck Winner, chairman of the CHRB at the time, issued a statement backing Baffert's claim, saying that Justify was among multiple horses cared for by different trainers that tested positive at the same time, an indication that contaminated feed was involved.

How the case was handled by the CHRB has come under scrutiny after the Times reported the governing body took more than three weeks to notify Baffert that the horse had failed a test, advising him only nine days before the Kentucky Derby.

It was more than a month before the CHRB confirmed the test result, the Times said, and it was four months later - after Justify had won the Kentucky Derby, Preakness and Belmont stakes to become the 13th Triple Crown winner - that the board voted at a closed-door executive session to dismiss the case.

AGENCE FRANCE-PRESSE