Jockey Michelle Payne has been stood down after being informed she has failed a drugs test.
A urine sample Payne provided earlier this month contained the appetite suppressant Phentermine – also known as – dimethylphenethylamine – which is a psychostimulant drug of the substituted amphetamine.
The 31-year-old became the first female Melbourne Cup winner in 2015 when riding Prince of Penzance to victory in the 156-year-old race, beating Max Dynamite and Criterion, who were second and third respectively.
Payne was informed of the failed drugs test on Friday, just three days after making her debut at Royal Ascot, and she has been stood down from racing until an investigation is completed.
Racing Victoria will conduct the inquiry into the results, which is scheduled for Thursday, and the female jockey could face a hefty suspension if she is found guilty of wrong doing.
Back in November 2012, jockey Frankie Dettori was handed a six-month worldwide ban for failing a drugs test in September that year.