The Lindsay Park training team has been hit with a $4500 fine after one of the stable's horses returned a positive result to the anaesthetic lignocaine.
A post-race blood sample from Madeira Bay, who won a maiden at Wagga on February 13, was found to contain the substance which is banned on race day.
David Hayes and Tom Dabernig gave evidence to the inquiry also acting on behalf of the third member of the training partnership, Ben Hayes.
Veterinarians Dr Dave McKellar and Dr Alex Tremlett and stable foreperson Russell Treloar also gave evidence but the inquiry was unable to establish the reasons for the positive swab.
The Lindsay Park trainers pleaded guilty on Thursday to bringing Madeira Bay to the races with a prohibited substance in her system.
After considering the training partnership's guilty plea, excellent record and forthright evidence, stewards fined the trainers and Madeira Bay was stripped of her win.