Swimmer Camille Lacourt says the newly-crowned Olympic 200m freestyle champion Sun Yang "p***es purple". The Frenchman – who finished fifth in the 100m backstroke final – has taken aim at the controversial Chinese swimmer, who served a three-month doping ban in 2014 after testing positive for trimetazidine.

The stimulant was added to the World Anti-Doping Agency's banned list four months before Yang failed a doping test, but the champion swimmer subsequently defended himself by claiming he was prescribed it to treat heart palpitations. He insisted, too, that he was unaware trimetazidine had been added to the banned list.

However, Lacourt has now waded in on the controversy, saying swimming was fast becoming like athletics "with two or three doped in each final". "Sun Yang, he p***es purple," Lacourt told French radio station RMCsport after his race.

"I am very sad when I see my sport getting like this. I have the impression I am looking at athletics, with two or three doped in each final. I hope that (swimming's world governing body) FINA is going to react and stop this massacre, because it is getting sad."

Earlier at the swimming meet, meanwhile, Australian Mack Horton took aim at Yang after beating him in the final of the 400m freestyle final. "I don't know if it's a rivalry between me and him, just a rivalry between me and athletes who have tested positive," he said of his dislike of the Chinese star, according to ABC News.

Mack Horton
Mack Horton won the 400m freestyle in Rio ahead of the Chinese star Adam Pretty/Getty

Elsewhere, the most-decorated Olympian in history, Michael Phelps, has insisted drug cheats should not be allowed back into sport. The 19-time Olympic champion admitted he was saddened by the cloud of suspicion that hangs over his sport.

"You're probably going to see a lot of people speaking up more. I think something needs to be done," Phelps said. "It's sad that today in sports in general, not just only swimming, there are people who are testing positive who are allowed back in the sport — and multiple times."

Meanwhile, Phelps' US teammate Lilly King – the newly-crowned 100m Women's breaststroke champion - has spoken out against her Russian rival Yulia Efimova, who has been allowed to compete in Rio despite previously serving a 16-month steroid ban and testing positive for meldonium earlier this year.

"I think it just proved that you can compete clean and still come out on top," King said after defeating Efimova to win gold. "I'm actually glad I made a statement, and I ended up coming out on top in the race." Efimova entered the Rio swimming pool to a chorus of boos.