Racing Victoria stewards confirmed on Monday morning that the Peter Moody-trained Brereton had returned a positive swab for a prohibited substance.

The result stems from a blood sample taken at Flemington on May 13, prior to the galloper finishing sixth in the Listed Straight Six (1200m) when beaten two lengths by the Danny O'Brien-trained It'sourtime.

The blood sample was shown to contain phenylbutazone and oxyphenbutazone (a non-steroidal anti-inflammatory and its metabolite) – banned substances under the Australian Rules of Racing.

“Phenylbutazone is a non-steroidal anti-inflammatory agent. It has analgesic (pain relieving), anti-inflammatory and fever suppression properties and is registered for use in horses by the Australian Pesticides and Veterinary Medicines Authority,” a Racing Victoria statement read.

“The substance is, however, a prohibited substance under the Australian Rules of Racing when detected in a sample taken from a horse at a race meeting or trial (including an official trial or a jumpout for the purpose of obtaining a permit to start in a race).”

RV stewards initially informed Moody of the irregularity on June 20, 2023.

Brereton is a one-time winner from 12 starts, with his sole career success coming in the Group 3 Maribyrnong Plate (1000m) on Melbourne Cup Day.