The father-and-son training partnership of Peter and Paul Snowden has been fined $7000 by Racing NSW stewards after a Newcastle winner returned a positive urine sample to a banned substance.

California Concorde returned a positive to phenylbutazone, oxyphenbutazone and gamma hydroxy phenylbutazone following a win on September 29.

A hearing on Wednesday found the positive sample was due to the inadvertent administration of phenylbutazone the day before California Concorde contested the Newcastle race.

The Snowdens pleaded guilty to a charge of taking California Concorde to race with a prohibited substance in its system with the galloper disqualified.

Credit: AAP