Two horses trained by two-time Triple Crown-winning Bob Baffert have reportedly tested positive for a banned substance—including an undefeated colt named Charlatan. The New York Times and Louisville Courier-Journal reported the positive tests came during a recent meet at Oaklawn Park in Arkansas. Charlatan was considered one of the top contenders for the Belmont Stakes on June 20—the opener for this year’s Triple Crown series—and won a split-division of the Arkansas Derby at the start of the month. The other horse to reportedly test positive, Gamine, won at Oaklawn on the day of the tests. The horses are said to have tested positive for lidocaine, a regulated anesthetic commonly used in equine medicine. Baffert has reportedly requested a second round of testing on his horses’ samples.