Jockey Danny Cook has been suspended for six months after testing positive for a banned substance.
The 31-year-old tested positive for benzoylecgonine, a metabolite of cocaine, at Musselburgh on 1 February.
Cook has not ridden since accepting an interim suspension by the British Horse Racing Authority last month.
Taking a Class A drug "the night before he was booked to take six rides, which he then rode, was a serious matter," the BHA said in a statement.
BHA spokesman Robin Mounsey added: "The ban will be backdated to when Danny stopped riding on 24 February."
Cook won the Plate at the 2010 Cheltenham Festival on Great Endeavour.