Jockey James McDonald has faced a Sydney court to again challenge an 18-month disqualification for betting on a horse he was riding.

The former Godolphin jockey has lost two appeals against the severity of the ban after admitting he placed a $1000 bet on his mount Astern in December 2015.

His lawyer, Bret Walker SC, told the NSW Supreme Court on Tuesday that racing stewards made an error in taking into account the mandatory minimum disqualification period when “special circumstances” applied to McDonald.

Justice Nigel Rein said he would hand down his decision within four weeks.

Credit: AAP