Davy Russell has been referred to the Irish Turf Club after failing to attend a dope test during racing at Naas yesterday.
Russell was summoned to the dope testing unit at the Kildare circuit but had failed to show before the last race.
A stewards' statement released on behalf of the track read: "The stewards received a report from Mr Al Guy, doping control officer, that DN Russell, rider, had failed to present himself for a dope test at the time required. And, having been given a fair chance to attend the dope testing unit, had still failed to attend by 5.33pm. Evidence was also heard from Mr Joseph Mallon, security officer.
"Having considered the report, the stewards referred this matter to the Turf Club for further investigation."