Medina Spirit 'never been treated' with steroid -Baffert

Baffert said a post-race sample provided by Medina Spirit had tested positive for 21 picograms of the anti-inflammatory drug betamethasone, over the legal limit in Kentucky racing.

The Louisville Courier Journal said betamethasone is a "man-made steroid that resembles cortisol, a natural hormone produced by the adrenal gland."

Medina Spirit, ridden by jockey John Velazquez had secured a half-length victory over Mandaloun in the 19-horse Kentucky Derby on May 1.

Baffert's camp was informed of the news by Kentucky officials on Saturday, but the 68-year-old denied giving the horse illegal substances and said the positive test was "the biggest gut punch in racing.