Sun Yang claimed gold in the 400m freestyle at the World Aquatics Championships in Gwangju, South Korea, on Sunday, finishing just ahead of Australia’s Mack Horton.

The latter, who has previously accused Sun of being a “drug cheat”, then refused to shake hands with Sun, share the podium presentation or pose for photos with him.

He did, however, shake hands and pose for a picture alongside Italy’s Gabriele Detti, who finished third in the race.

Sun, who was banned for three months in 2014 for testing positive to banned stimulant trimetazidine, said he felt sorry about Horton’s reaction.

“Disrespecting me was OK, but disrespecting China was unfortunate,” the new world champion told reporters after the medal presentation.

“I feel sorry about that.”

Horton, however, stood his ground and made his feelings known when he spoke to the media after the race.

“I just won’t share a podium with someone that behaves in the way that he [Sun] has,” the Australian said.

“I don’t think I need to say anything. His actions and how it has been handled speaks louder than anything I could say.”

The feud between Sun and Horton stretches back all the way to the 2016 Olympics in Rio de Janeiro, Brazil.

Horton, who won the gold medal in Rio ahead of Sun, accused his Chinese rival of deliberately splashing him during a training session.

“I ignored him, I don’t have time or respect for drug cheats,” he said at the time.

“I just have a problem with athletes who have tested positive and are still competing.”

When Sun was suspended in 2014, he claimed he had been taking the stimulant because of a heart complaint. Last year, however, the Chinese athlete again found himself in the spotlight after he was accused of missing a doping test at his home in September 2018.

Sun defended himself by saying he did so as he doubted the testers’ accreditation and FINA—the international swimming federation—doping panel cleared him of any wrongdoing.

However, the World Anti-doping Agency appealed the decision and Sun faces a new hearing at the Court of Arbitration for Sport in September.

Last week, Australia’s Daily Telegraph newspaper published a 59-page leaked report by FINA following the hearing at which Sun explained why he refused to comply with the drugs test.

Sun has now won the gold medal in the 400m freestyle at the last three editions of the World Aquatics Championships, adding to the gold medal he won in Rio in the 200m freestyle.

He won the gold medal in the same discipline in the world championship a year later, adding to the silver medal he won at the 2015 world championship, when he also claimed gold in the 800m freestyle.

Horton, meanwhile, did not qualify for any event in Gwangju but was given the nod by Australian selectors anyway.