Sydney - Australian champion swimmer Mack Horton insisted on Saturday his bitter feud with Sun Yang was never personal and always about ensuring the sport was clean after the Chinese star was banned for eight years.

The Olympic 400m gold medallist famously snubbed his rival for a photo-call and refused to shake his hand after a medal ceremony at last year's world championships in South Korea, reigniting a row from the 2016 Rio Olympics where Horton labelled Sun a "drug cheat".

His actions appeared vindicated when Sun was found guilty by the Court of Arbitration for Sport (CAS) on Friday of refusing to give a doping sample and banned for eight years.

It was a crushing blow for the triple Olympic gold medal winner, who is idolised in China and vowed to appeal, calling the verdict "unfair".

While Horton's stance won widespread support within the swimming community, it provoked a furious reaction in China with his Instagram account trolled, some even posting death threats.

"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 Seven en route to a pre-Olympic training session on Saturday.

"It goes on," he added when asked if he was relieved at the outcome. "I'm just a guy still chasing the dream... we've got a job to do this morning and we'll just keep going."

The CAS decision upheld an appeal by the World Anti-Doping Agency (WADA) against swimming's ruling body FINA and Sun, who had already served a three-month doping ban in 2014.

Sun was accused of refusing to provide blood and urine samples when drug testers visited his home in China in September 2018.

Australian media revelled in his downfall with the Sydney Morning Herald saying: "Career-ending ban vindicates Horton's contempt for star."

"His legacy will always be linked to that of Sun, a now semi-tragic figure who will be revered as a sporting martyr in China regardless of the CAS ruling," it added.

"Horton's reputation as an athlete leader in the fight for clean sport will forever be assured."

The Sydney Daily Telegraph took a similar stance, headlining: "Mack Horton's crusade vindicated."

"Subjected to death threats to him and his family, snubbed by gutless sponsors frightened of alienating Chinese consumers and reprimanded by the sport's out-of-touch administrators, Horton has already paid too high a price for taking a stand against doping," it wrote.

With Sun sidelined, Horton will now be hot favourite for the 400m gold at the Tokyo Olympics.

Australian great Ian Thorpe told reporters that he "definitely supported Mack's stance".

"I also felt that the sport should've done a better job in making sure there was never a situation where Mack had to stand up on the podium in the first place," he added.

David Sharpe, who heads the Australian Sports Anti-Doping Authority, said the CAS ruling "restores faith in the anti-doping system".

"We hold our athletes to the highest possible standards and we expect that those standards are upheld globally," he added.