Trainer Corine Barande-Barbe has asked the police to make enquiries into the positive sample returned by Cirrus Des Aigles after his run in the Prix d'Ispahan at Longchamp in May.
Barande-Barbe suspects foul play could be the reason last season's Champion Stakes winner tested positive for "a massive" dose of an anti-inflammatory drug when he finished second to Golden Lilac.
Barande-Barbe said: "I went to the police on Saturday to complain against it. I'm very surprised and very afraid because if someone can get to the horse they could kill him. If it happens to us, it can happen to anybody. If people begin to hate and are jealous it is terrible. I communicated about the problem as soon as I knew about the positive result because I always communicate easily and I have nothing to hide."
She went on: "We are sure we didn't give him anything - I am confident in my yard. People can only get into his box with a key."
Barande-Barbe feels unless the situation is cleared up, she will be tarnished for the rest of her career, adding: "To do such a thing means you are completely judged. I've asked France Galop (French racing authorities) to keep the samples but they said it's not in the French rules to keep the samples - I said it's not in the rules to destroy them either. I think I would prefer it if there was a problem with the sample. It would be very difficult to prove if somebody has given him something. The vet told me it is likely he has been given it the night before or on the morning of the race as it is so strong.
"Nobody would be stupid enough to give him something then - this horse doesn't need anything. He has been tested so many times he was always going to be tested this day as he was favourite. That day he didn't run better than ever, on the contrary. It is so surprising. If he had won by 10 lengths maybe you could say someone gave him something but not then. The dose is so massive it makes no sense. I don't want to think there has been an error but we will ask them (France Galop) to analyse again.
"Anywhere else in the world - Ascot, Meydan, Hong Kong - nobody goes to the stables, yet at Longchamp everybody goes to the stables and they can hurt your horse. I think the story is not finished at all."
Julien Pescatore, media relations manager for France Galop, confirmed an enquiry into the positive sample was currently taking place. Any disciplinary action would not be taken until the end of the enquiry.
Prescatore said: "An enquiry is currently going on by the veterinary chief of France Galop. There will be no action taken until the enquiry is finished so Corine Barande-Barbe will be allowed to continue training and Cirrus Des Aigles will be allowed to run. We need to wait for the conclusion of the enquiry but we don't know how long it will be.
"There were two samples. One was sent to a French horseracing laboratory and they found a high does of an anti-inflammatory drug. The other was then sent to a laboratory in Newmarket and showed the same. We are now waiting for the conclusion of the enquiry."