Trainer Sam Kavanagh faces a lengthy ban after being found guilty of 23 charges relating to the use of cobalt and race day treatments.

The long-running inquiry was sparked by the presence of cobalt and caffeine found in a sample taken from the Kavanagh-trained Midsummer Sun after he won the Gosford Cup in January.

The investigations by Racing NSW stewards and the integrity unit resulted in five other people, including Kavanagh's vet Dr Tom Brennan, being charged and also found guilty of 12 charges including lying to the original inquiry.

Kavanagh named Brennan, the principal of the Flemington Equine Clinic, as the source of a substance called Vitamin Complex which was found to contain 175 times the amount of cobalt usually found in a supplement.

The clinic's manager, Aaron Corby has been found guilty of one of two charges, that of trying to persuade Kavanagh not to name Brennan or the practice as the source.

Disqualified harness racing trainer Mitchell Butterfield and harness racing identity John Camilleri were also found guilty of drenching horses in the stable on race days.

Michael O'Loughlin, a Kavanagh stable foreman who has declined to appear before stewards, has been found guilty of assisting Butterfield and charged with not attending the inquiry.

Brennan has also been charged in Victoria in the cobalt inquiries involving trainers Danny O'Brien and Mark Kavanagh, the father of Sam.

O'Brien and Mark Kavanagh are among five trainers to face stewards later this year.

Racing NSW stewards will consider written and oral submissions on penalty on September 10.