Aidan O’Brien pulled all four of his horses from the Prix de l’Arc de Triomphe on Sunday in Paris after they tested positive for a banned substance.
It is suspected that the banned substance was in contaminated feed.
Ireland coach Mogul was set to run Japan, Serpentine and Serene in Europe’s richest race, which Enable is striving to win for a record-breaking third time.
His sons Joseph and Donasha also pulled the horses in which they were scheduled to run in other races at the meeting.
A total of 11 Triple Trained Horses will be absent.
“Unfortunately, the results of urine samples taken from horses were positive from the French laboratory,” read a statement issued by the O’Brien Bladwell Racing base.
“There is a possibility that the polluter left its system by race time on Sunday, but we have no guarantee for that.
“In order to protect the safety of racing, we decided to withdraw all of our horses from racing (on Sunday).
“Joseph and Donasha O’Brien will do the same.”
British trainer Roger Varian, who uses the same feed provider, pulled the seven intended runners from the meetings on Saturday.
On Friday night, Aidan O’Brien’s runners’ ability to run the ParisLongchamp match came into question.
France Galop announced that five horses have tested positive for the banned substance Zilpaterol, which is suspected to be in contaminated animal feed.
O’Brien’s riders in France on Saturday got the green light for the race after urine samples sent to the Irish Equine Center were clearly visible.
But their ARC competitors are yet to get the green light, and withdrawals will overshadow a highly anticipated match.
Aidan O’Brien’s opponent, Love, was pulled earlier in the week after the referee was torrential rain.
The quadruple absence leaves Enable, the Frankie Dettori Mountain of British coach John Gossden, against 10 rivals – with the stadium shrinking from 15 to 11. She is now the public favorite for a historic success.
Aidan also knocked St Mark’s Cathedral out of the Jean-Luc Lagardaire Grand Prix as the horses trained by the O’Brien family were pulled from a total of three other races in Group A.
Joseph was set to lead the competition to Pretty Gorgeous in the Prix Marcel Boussac, while Fancy Blue would miss the Prix de l’Opera for Donnacha.