LONDON -- One of Queen Elizabeth II's racehorses has failed a doping test.
Six-year-old Moonlit Path tested positive for a banned substance that prevents hemorrhaging after a sixth-place finish in her debut February at Huntingdon.
Trainer Nicky Henderson has been charged with breaching two rules by the British Horseracing Authority.
The queen's racing manager, Michael Oswald, described it as "very disappointing news" and told British media that the monarch had been informed.
The BHA said Henderson was responsible for the horse being given tranexamic acid "with the intention of affecting her racing performance or in the knowledge that her racing performance could be affected by such."
A hearing is set to be held in June.
Henderson acknowledged the use of the substance, but said it was not used as doping.
"The substance concerned was administered by my vet entirely in the interests of the horse's welfare, which is always paramount," Henderson said. "There was no intention to enhance performance and it is worth pointing out that we won the race in question with the odds-on Ravello Bay."
Moonlit Path has run twice since her debut, finishing fourth out of 13 on both occasions.