The FINA Executive on Monday sent a warning letter to Swimming Australia Ltd. and athlete Mack Horton over his behavior during the men's 400-meter freestyle victory ceremony at the world championships in Gwangju, South Korea.

China's Olympic champion Sun Yang won his fourth straight world title in the event and his 10th at the FINA World Championships in the South Korean city on Sunday.

During the awarding ceremony, Horton did not step onto the podium after claiming a silver medal in the event.

"The FINA Executive met today (Monday) in Gwangju to analyze the situation related with the men's 400-meter free victory ceremony and decided to send a warning letter to Swimming Australia Ltd. and to athlete Mack Horton," FINA said in a statement.

"While FINA respects the principle of freedom of speech, it has to be conducted in the right context."

"As in all major sports organizations, our athletes and their entourages are aware of their responsibilities to respect FINA regulations and not use FINA events to make personal statements or gestures," the organization said.

The statement added: "The matter over which Mack Horton was allegedly protesting is currently under review by CAS and therefore it is not appropriate for FINA to prejudice this hearing by commenting further."

Sun requested a public hearing at the Court of Arbitration for Sport (CAS) to defend his innocence against alleged anti-doping rule violations.

(With input from Xinhua)