Australian trainer Darren Weir faces a ban of four years after deciding not to contest charges brought against him for the possession of equipment used to deliver electric shocks to horses.
Police seized four of the illegal Taser-type devices at the Melbourne Cup winner's stables on 30 January.
At a hearing with Racing Victoria, Mr Weir, 48, said he would not contest three charges brought against him.
Assistant trainer Jarrod McLean will contest some of the charges he faces.
Charges against a third man, Tyson Kermond, of failing to assist the stewards will not be pursued.
Weir is one of Australia's top trainers and claimed a landmark victory in the 2015 Melbourne Cup when jockey Michelle Payne won aboard Prince Of Penzance,
"Darren Weir is facing serious charges of possessing three electrical apparatus and conduct prejudicial to the interests or image of racing," said Jamie Stier, Racing Victoria's executive general manager - integrity.
"He has advised the stewards that he will not contest those charges which have drawn considerable negative publicity to the sport."
Last week police seized a firearm, a substance believed to be cocaine and the electronic devices at the Melbourne Cup winner's stables.
The devices are known as 'jiggers' and can cause horses to run faster in conjunction with a jockey using their whip.
"Given the severity of the charges, stewards will be seeking disqualification for a period of four years," said a Racing Victoria statement.
"Mr Weir was informed that this was the stewards' position before he determined not to contest the charges."
He is effectively banned from running horses until a hearing on the charges takes place on Wednesday.