Newmarket trainer Gerard Butler has been charged by the British Horseracing Authority after nine of his horses tested positive for a banned substance.
The charge relates to the use of the drug Sungate, which contains the banned anabolic steroid, stanozolol.
Butler alerted the BHA that his vets had administered the banned substance, which is considered legal when it is imported under licence, but it is regarded as prohibited in the sport.
He will now be required to attend a disciplinary hearing at a later date.