China's Sun Yang is awarded for best male swimmer of the championships, at the Aquatics World Championships in Kazan, Russia, Aug 9, 2015. [Photo/Agencies]

Sun appeared at the end of the night to receive the best male swimmer award. He won the 400 and 800 freestyles in Kazan and was a strong favorite in the 1,500, which he won at the London Olympics. Sun finished second in the 200 free.

Brazil men's coach Alberto Silva told The Associated Press there was an incident in the warmup pool Sunday morning when one of his female swimmers was in the same lane as Sun, though Silva did not think it was the reason why Sun didn't compete.

"There was a discussion," said Silva, adding that no one was injured. "It's a short girl and a big guy. He went across (her)."

Silva said he complained to officials of world governing body FINA, and they spoke to a Chinese team official.

"(The Chinese) came to the Brazilians and said sorry. That's it," said Silva, who declined to identify the Brazilian swimmer.

Brazil team spokeswoman Eliana Alves said there was contact between Sun and the Brazilian athlete "but it was not a fight."