Racing Victoria stewards have confirmed another positive test for an anti-inflammatory drug in samples taken from a horse that competed at Sandown in July.
Trainers Darren Weir, Henry Dwyer and Simon Morrish have been charged after horses from those stables tested positive to Phenylbutazone and its metabolite Oxyphenbutazone at the Burrumbeet trials in August.
Geelong trainer Kelvin Bourke also faces a stewards' investigation after Can't Refuse tested positive to the drug after its unplaced run in the Le Pine Funerals Handicap (1800m) at Sandown on July 26.
Stewards advised Bourke of the initial results of analysis of blood and urine samples on August 31 before notifying the trainer of the confirmatory results on Monday.
The investigation is continuing.