A firestorm hit Chinese social media after Australian swimmer Mack Horton called Chinese rival Sun Yang a drug cheat.  And now Sun is hitting back.  He told an Australian reporter that he doesn't know Horton and that he will be the king of the 1500-meter freestyle final.

Mack Horton, who won the 400-meter freestyle, had less than encouraging words for the second place finisher Sun Yang, calling him a "drug cheat". That was in reference to the Chinese swimmer serving a three-month suspension for taking a banned heart medication. The remarks have drawn wide criticism on the Internet and social media.

The Sydney Morning Herald reports that Horton acknowledged it was "a deliberate ploy to get into the head of his main rival". China's Swimming Association has issued a formal email, asking Horton to issue an apology.  On Sunday, IOC spokesperson Mark Adams said he didn't know of the incident, and that he needed to look into it.