The vet named as the supplier of Vitamin Complex, the substance at the heart of the Sam Kavanagh cobalt case, has been charged with six offences.
Dr Adam Matthews, who worked at the Flemington Equine Clinic with Tom Brennan, was charged in September but Racing NSW stewards were unable to make them public because of an injunction obtained by the vet.
Stewards confirmed the charges on Friday.
Samples taken from Midsummer Sun after he won the Gosford Cup in January, showed a high level of cobalt sparking the inquiry which has had a heavy attrition rate including his trainer Kavanagh and Brennan who have both been disqualified.
Kavanagh named Brennan as the source of Vitamin Complex which has a high concentration of cobalt with Brennan naming Matthews as his source.
The charges against Matthews relate to two bottles of Vitamin Complex he supplied to Brennan who in turn supplied them to Kavanagh.
The charges include supply of the prohibited substance and improper conduct in doing so.
Matthews will face stewards next week with two days set down for the hearing.
Kavanagh and Brennan have appealed their bans.