Newmarket trainer Gerard Butler has vowed to help the British Horseracing Authority in any investigation related to alleged steroid use in his yard.
The 47-year-old revealed to The Independent that several of his horses had been given substances to help treat certain injuries, but insisted that he has not broken any rules.
Following the eight-year ban issued to Godolphin trainer Mahmood Al Zarooni for using anabolic steroids on horses, Butler has become wary of a possible probe.
"Over the last few days I have been very uneasy about the Al Zarooni case and felt that I needed to let the general public know what has happened in my yard," Butler told BBC Sport. "Now I would like only to concentrate on helping the BHA with their investigation."
The case involving Al Zarooni also resulted in 15 horses being suspended from racing for six months.