Successful Victorian training partners Bill and Symon Wilde are set to face a stewards' inquiry over a positive swab.

A horse in the care of the co-trainers tested positive after winning on debut at Warrnambool.

Racing Victoria confirmed on Tuesday a post-race urine sample taken from Great Lane after its maiden win on March 4 contained phenylbutazone and oxyphenbutazone, a non-steroidal anti-inflammatory.

The Wildes, who are based at Warrnambool, have been advised and Racing Victoria stewards are continuing their investigation.

They trained a winner during last week's three-day Warrnambool May Racing Carnival.