Barbary Castle handler Alan King is set to face a BHA disciplinary panel on Thursday after it was revealed that Yanworth failed a drugs test following the Champion Hurdle in March.
Owned by JP McManus, the son of Norse Dancer was supported into favouritism for the two mile feature on day one of the Cheltenham Festival but finished a distant 14-length seventh behind Buveur d’Air, also owned by McManus.
Post-race it was discovered that the seven-year-old had traces of triamcinalone acetonide [TCA], an anti-inflammatory substance which may be legitimately used on horses in training but is banned on race day.
King will not attend the inquiry, during which the panel will consider whether to disqualify Yanworth.
After Cheltenham, he went on to win the Liverpool Hurdle over three miles on Grand National day.
It is not the first time one of King’s horses has tested positive for TCA, with Midnight Cataria disqualified from second place at Kempton in October 2015 after the drug was detected in her system.
King and the BHA agreed the source of the drug was the trainer’s vet, who had treated the mare for lameness, with TCA remaining in her system longer than anticipated. He was subsequently fined £1,000.