French swimmer Camille Lacourt claims Sun Yang "p***** purple" after he won gold in the 200 metre freestyle at Rio 2016.
Sun served a three-month suspension after testing positive for banned stimulant trimetazidine in 2014 and his appearance at Rio 2016 has caused controversy, with Australian Mack Horton particularly critical.
The Chinese was beaten to gold in the 400m freestyle by Horton, but topped the podium in the 200m final as Lacourt finished fifth.
The Frenchman was vehemently critical of Sun's participation at the Games, but wants to take positive memories away from the event.
"Sun Yang, he p***** purple," Lacourt said in an interview with French radio station RMC.
"I do not like not being on the podium. It displeases me to be beaten by a Chinese.
"When I see the podium of the 200 metre free it makes me want to be sick.
"I prefer to remember the crowd that screamed when we went out and the Olympic pool, which is great."
There was also controversy in the women's 100m breaststroke, with Lily King outspoken in her disappointment that Yuliya Efimova had been granted permission to compete at the Games despite a provisional suspension for meldonium use this year.
Lacourt called on the International Swimming Federation (FINA) to take more decisive action and save the reputation of the sport.
"I am very sad to see my sport going this way," added Lacourt.
"I have the impression I am looking at athletics, with two or three doped in each final.
"I hope that FINA will react quickly and stop this massacre, because it is becoming sad."