Japanese thoroughbred Deep Impact has been disqualified from a third-place finish in last month's Arc de Triomphe, after testing positive for a banned substance.
Deep Impact will retire to become a breeding horse
The horse's trainer Yasuo Ikee has also received a 15,000 euros fine (£10,100).
Deep Impact's third place has now been awarded to Hurricane Run, ridden by Kieren Fallon.
Deep Impact is considered one of Japan's best-ever race horses, but tested positive for Ipratropium - an inhaled medication that aids breathing.
A statement from France Gallop, who organise racing in Paris said the substance had been used as a veterinary treatment.
After the positive test was announced the trainer said he was "very surprised".
The owner and the trainer of Deep Impact will not appeal against the decision. Deep Impact will now retire to become a breeding horse.