Leading Australian rider James McDonald has stood himself down from riding after being charged with either betting on, or being involved with a bet, on one of his mounts at Randwick last year.
McDonald, who is stable jockey to Godolphin's head Australian trainer John O'Shea, is alleged to have had a betting interest in Astern, whom he partnered to victory at the Sydney track on December 5, 2015.
Racing New South Wales stewards announced the charges on Tuesday, immediately interviewing McDonald after acting on what was described as intelligence received.
Following the interview, Racing NSW stewards issued a charge against McDonald, citing a rule concerning penalising any rider "if he bets, or has any interest in a bet on any race or contingency relating to thoroughbred racing involving a race in which he is riding. For the purposes of this rule, a bet includes a lay bet".
McDonald was not required to enter a plea and the stewards accepted his request to be permitted to voluntarily stand himself down from riding immediately, pending the hearing of the charge.
A date has yet to be fixed for the charge to be heard.
McDonald enjoyed a lucrative spell in Britain over the summer, partnering the likes of Dutch Connection to win the Lennox Stakes at Goodwood, Big Orange to lift the Princess Of Wales's Stakes at Newmarket and Antiquarium, who landed the Northumberland Plate.