Aussie swimming champion Mack Horton has received death treats on social media after a bombshell anti-doping verdict banned bitter rival Sun Yang for eight years.

The Court of Arbitration for Sport (CAS) on Friday night (AEDT) accepted an appeal from the World Anti-Doping Agency (WADA) against a decision by swimming body FINA to clear Sun of wrongdoing for his conduct during a 2018 drugs test.

The CAS said the eight-year ban was imposed because Sun already had an earlier anti-doping rule violation against him from 2014.

Despite the verdict, a defiant Sun has vowed to appeal and fight to save his career.

China’s top swimmer declared the CAS verdict was “unfair” and his supporters echoed his beliefs in a series of trolling attacks on Horton’s social media pages.

Fans, writing in English and Chinese characters, issued strange death threats to Horton.

The 23-year-old’s Instagram and Twitter pages were lightning rods for Sun supporters to direct their anger towards after the three-time Olympic champion’s doping ban was enforced.

One comment on Instagram translated from Chinese told Horton to “rest in piece” and asked the Aussie swimmer when he would “die”.

Another comment in English said: “Your mom just dead”.

Another Instagram user wrote: “You see you are born to have only the life of garbage”.

Another blamed Horton for insulting Sun Yang first with his iconic silent podium protest at the World Championships.

“Mack Horton jumped out first to insult Sun Yang. It’s really impolite,” one Instagram user wrote.

“Does he think he is a god who knows all the truth?”

Tens of thousands of Chinese flooded social media in support of Sun Yang following the verdict, stating it was “cruel” and “unjust”.

“Foreigners are jealous. It is really unfair to treat Sun Yang in this way. Since when did competitive sports become villain sports,” said one user called ‘Lingering memories’ on microblogging website Weibo Corp.

Horton has repeatedly been attacked by social media trolls and was last year also targeted with death threats following his podium protest at the FINA Swimming World Championships in Gwangju.

However, the Aussie responded to Sun’s suspension by suggesting the ongoing campaign against doping cheats in professional sport is still ongoing.

“I think regardless of the outcome it was always going to be a statement to the world and my stance has always been about clean sport never about nations or individuals,” Horton told Channel 7.

When asked if he is feeling a sense of relief or vindication, Horton replied: “It goes on.

“I’m just a guy still chasing the dream... we’ve got a job to do this morning and we’ll just keep going.”

Despite the heavy toll the saga has taken on Horton, Australia’s swim team head coach Jacco Verhaeren said before Sun’s verdict was handed down that he expects the doping case to barely cause a ripple amongst his team.

“Mack is a very focused athlete, he’s not easily distracted and he won’t be distracted by this either,” Verhaeren said on Friday.

“He has dealt with situations like this before and never gets distracted so he won’t be in this case.

“He made his stance. His stance won’t change and that is fine. “But we’re not in the business of commenting on foreign athletes or whatever the outcome is.”

The Australian team is trying to move forward and keep their focus on this year’s Tokyo Olympics after declaring it would accept the verdict of the CAS — no matter what verdict was handed down.

Sun, however, is refusing to accept his suspension.

“This is unfair. I firmly believe in my innocence,” he told Xinhua.

“I will definitely appeal to let more people know the truth.”

WADA, meanwhile, welcomed the CAS ruling as “a significant result” in a separate statement and said it was “satisfied that justice in this case has been rendered.”

— with AAP