The Irish show jumping gold medallist whose Olympic horse tested positive for a prohibited substance last week disclosed on Sunday that another of his horses has also tested positive.
Cian O'Connor, 24, revealed in an interview with RTE state television that a second horse, ABC Landliebe, tested positive after a show jumping event in Rome in May.
An emotional O'Connor again said he was not a cheat and denied he was guilty of any wrongdoing.
"I have nothing to hide, I have done nothing wrong", he said.
O'Connor risks being stripped of the gold medal for his victory in the individual show jumping event in Athens after his horse Waterford Crystal tested positive.
It was Ireland's only Olympic medal at the games and the country's first ever in an equestrian event.
The show-jumper, who became a national hero and was feted when he arrived home from Athens, has exercised his right to have a second sample taken from Waterford Crystal tested.