Horton, 20, won Australia's first gold medal at the Rio Olympics when on day one he powered to victory ahead of Sun Yang, who Horton had labelled a "drug cheat" following the heats. "I used the word 'drug cheat' because he tested positive," Horton said when pushed by Chinese reporters after the final. "I just have a problem with him testing positive and still competing." Most of the Australian swimmers firmly agree with what Horton has said and the stance he has made. In 2014, Sun Yang served a three-month ban after testing positive for a banned stimulant. The China Anti-Doping Agency – the great crusader against doping that it is – announced he had tested positive for trimetazidine, a substance normally used to treat angina.

The stimulant was added to the World Anti-Doping Agency's banned list that year. The rest of the world was told of Sun's positive test after he had served the ban. "I have taken many doping tests during years of training and competition and I had never failed one before," Sun told China's official Xinhua news agency at the time. "I was shocked and depressed at that time, but at the same time it made me cherish my sporting life even more. I will take it as a lesson and be more careful in the future." Of course, the whole thing reeked. It usually does. China's anti-doping lab was suspended by WADA earlier this year for four months. Some will argue the burden of proof rests with Horton. That Sun Yang hasn't tested positive to a steroid, rather some docile heart medication. That we should look in our own backyard before we look into others. And while Horton has since admitted his drug cheat jibes were all part of an elaborate plan to mentally disintegrate his rival in the pool, it tapped into a growing feeling that these Olympics will be remembered for the scourge of doping as much as its headline moments.

Before the evening session on day two, the talk around the Aquatic Centre hadn't been so much about whether Michael Phelps and the US could win the men's 4x100m freestyle relay, but about Russia's Yulia Efimova. She was greeted during her preliminary heat of the 100m breaststroke with boos from the crowd following two weeks of insanity in which she was in then out then back in. Following the handing down of WADA's McLaren Report into systemic doping by Russia, the IOC had made it clear that any Russian athlete who had been previously sanctioned for doping could compete in Rio. Efimova has twice tested positive for banned substances, once in 2013 for which she served a 16-month suspension. Earlier this year, she tested positive to the newly banned substance meldonium, but she was found as having "no fault". The 24-year-old was one of seven Russian swimmers banned but was allowed back in at the 11th hour after a ruling from the Court of Arbitration for Sport that few can understand.

The public, though, are no fools. The echo of boos that greeted her showed the dissatisfaction that remains around the Russian team. If you are angered as a spectator and lover of sport, imagine standing on the blocks as a competitor, one eye on the water ahead of you, one on the rival next to you who may or may not be clean. When Phelps said, "I don't think I've ever competed in a clean sport" on the eve of these Games, it was a rare condemnation of the sport and the way it is policed. Athletes are so well versed in what they say to the media about doping, they sound like politicians. Notice how many of Phelps' teammates have backed him up – none. Horton did, though.

Loading And while he doesn't have the weight of a man who has won 18 gold medals, let's applaud him for speaking up after winning one. Someone has to.