High-profile businessman Gerry Harvey is among those prepared to support trainer Sam Kavanagh in a return to racing once he serves his penalty for cobalt use.

Paul D'Angelo, counsel for Kavanagh, made submissions on penalty to Racing NSW stewards on Thursday arguing it should not be so severe as to prevent Kavanagh returning to the industry which has been his life.

Kavanagh has been found guilty of 23 charges relating to cobalt use and race day treatments sparked by positive results in a post-race swab from Midsummer Sun after he won the Gosford Cup in January.

D'Angelo said although several of the charges carried mandatory suspension or disqualification, there was a case for them to be served concurrently rather than cumulatively.

He cited Kavanagh's co-operation with authorities which led to others being charged, his personal circumstances and his remorse as factors to consider.

"It was a one-off series of events borne of extreme pressure," D'Angelo said.

"You can send all the appropriate messages to the community with a penalty that's not crushing to him.

"He still has a debt of $70,000 to the Flemington Equine Clinic. He is unlikely to retain his own vehicle and he and his wife and daughter are moving from place to place.

"The penalty should enable him to return sooner rather than later."

He also tabled character references on behalf of the trainer including one from Harvey who operates the Magic Millions horse sales and race day and is a prominent owner-breeder in addition to his retail interests.

"Sam has been honest and up front in all transactions I have had with him," Harvey said.

"I would happily send him more horses to train when his disqualification comes to an end."

Kavanagh will serve a mandatory three-year ban for the administration of cobalt to three horses - Midsummer Sun, Centre Pivot and Spinning Diamond.

"I understand seven other charges of race day treatment carry six months minimum and four charges have two years minimum attached to them," D'Angelo said.

He said the special circumstances around the case should lead to flexibility in sentencing and to concurrent penalties.

Kavanagh's confessions to stewards led to charges against Flemington Equine Clinic vet, Dr Tom Brennan, who he named as the source of a substance later found to contain high levels of cobalt.

Brennan, the clinic administrator Aaron Corby, harness racing identities Mitchell Butterfield and John Camilleri and stablehand Michael O'Loughlin have all been found guilty in relation to the case.

Stewards will hear submissions on behalf of Brennan and Corby on Friday week after which they will hand down all the penalties.