On Saturday, the Australian freestyler Mack Horton was in the warm-down pool before the competition when Sun, his main rival, vigorously splashed him, as if to get his attention.  Sun served a three-month suspension in 2014 for taking a banned stimulant.  “I ignored him,” Horton, 20, said, “because I don’t have time or respect for drug cheats.”  That night, Horton out-touched Sun for the gold medal in the 400-meter freestyle. Horton did not acknowledge him in the water and later called it “a win for the good guys,” although he and Sun did shake hands during the medal ceremony.  Members of the Chinese swimming team expressed outrage about Horton’s actions, with the team manager Xu Qi calling for an apology. None has been forthcoming.  “Mack obviously has very strong views about the need for clean sport, as every single one of us does,” said the Australian delegation’s chef de mission, Kitty Chiller. “He has every right to express his views and his displeasure in that sense.”  The current Olympians Dana Vollmer and Cody Miller and past winners weighed in on the doping controversy at the Rio Games that has resulted in tiffs between Lilly King and Russian swimmers who were booed.  Sun went on to win the gold medal in the 200-meter freestyle Monday night.  “They don’t belong in a sport,” Camille Lacourt, a star French swimmer, said Monday night in comments reported by the French newspaper L’Équipe. “They should make up their federation of dopers and have fun among themselves. It disgusts me to see people who’ve cheated standing on podiums. Sun Yang, in the 200 free, he pees purple.”  That night, the American swimmer Lilly King, 19, cited Horton as an influence when she spoke out about Efimova.  King entered the Rio Games with the top time in the world this year in the women’s 100-meter breaststroke. The next-fastest swimmer in the lead-up to the competition was Efimova, a 24-year-old Russian whose place at these Olympics was not confirmed until Saturday.  Efimova, the reigning world champion, had served a 16-month doping suspension handed down by swimming’s global governing body, known as FINA, a ban that ended in early 2015. Early this year, Efimova failed a test for the newly banned drug meldonium, but the result was overturned when she appealed to the Court of Arbitration for Sport, arguing that she had already served her penalty.  Every time Efimova has raced inside the Olympic Aquatics Stadium, she has been booed. King demonstrated her disapproval in another way. After posting the fastest time in qualifying on Sunday afternoon, King wagged her finger to remind everyone who was No. 1.  As King looked on from the ready room, where swimmers gather before they race, Efimova won the first semifinal and mimicked King’s move. King went out and won the second semifinal and shook her finger again.  A spokesman for the International Olympic Committee said that fans want “fair play” from athletes amid tensions over doping and that the I.O.C. president, Thomas Bach, wants a life ban for serious doping.  In a postrace interview with NBC, King said, “You wave your finger No. 1, and you’ve been caught drug cheating?”  She added, “I’m not a fan.”  In a group interview in the mixed zone, King defended her actions. “I’m not this sweet little girl,” she said. “That’s not who I am.”  All the finger wagging set the stage for the final on Monday night, when their score was settled in the pool. King occupied Lane 4. Efimova was in Lane 5. It was a duel at 100 meters. King turned first at the 50 and hung on to win with a time of 1 minute 4.93 seconds. It was her best time and an Olympic record. Efimova was second in 1:05.50, 19-hundredths of a second ahead of King’s American teammate Katie Meili.  After the race, King hung on the lane line that separated her from Efimova and splashed twice in Efimova’s lane. King said she had not done it on purpose. But she also studiously avoided contact with Efimova.  “I don’t think she really wants to be congratulated by me,” King said.  The news conference featuring the medal winners felt more like a trial than a triumphant review. King sat at the opposite end of the table from Efimova. Meili was in the middle seat, normally reserved for the gold medalist. Neither King nor Meili looked at Efimova, who was on the verge of tears from the opening question about the boos directed at her.  “I’m just happy I’m here and racing,” said Efimova, who looked miserable. She appealed to people “to try to understand me,” but King, who sat stone-faced through Efimova’s answers, did not appear moved.  Sam Manchester will guide you through the 2016 summer Olympics in Rio de Janeiro.  Hey. It’s Sam from the NYT Sports desk. I’m at the Olympics in Rio (so you don’t have to be :)). Grab a limited spot and I’ll text you updates, answer your questions and share the behind-the-scenes stuff nobody else gets.  Thanks! Talk to you soon.  U.S. numbers only. Standard messaging rates may apply. Your information is used only to deliver messages about the Rio 2016 Olympics.  At one point, Efimova switched from English to Russian. The moderator nudged a pair of headphones toward King and told her she could use them to listen to the English translation. King declined, as did Meili.  What is striking is that the antidoping chorus in Rio has consisted of newcomers and veterans alike, with Olympic rookies like Horton, of Australia, and King joining the 31-year-old Lacourt and Michael Phelps, who is also 31 and is the most decorated athlete in Olympic history.  “I think what you’re seeing is the desire of Olympic athletes to uphold the values of the Olympic Games without exception,” Adam Nelson, an American shot-putter and activist for athletes’ rights, said in an email Monday.  Nelson was named the winner of the 2004 Olympic shot-put competition eight years after it was contested when the original champion, Yuriy Bilonog of Ukraine, retroactively tested positive for a banned substance.  “These athletes know, when an athlete cheats, he or she will experience a residual physical benefit for many years,” Nelson added. “But there’s also a residual sentiment that negatively impacts the sport moving forward. The clouds of suspicion that linger over doped athletes who return to competition continue to take a toll on the value of the clean athlete.”  There is not yet conclusive evidence on the long-term benefits to performance for athletes who took banned substances earlier in their careers. And as Thomas Bach, the I.O.C.’s president, has repeatedly pointed out, lifetime bans from sports for doping offenses have not proved legally defensible. In the cases of men like Sun and Justin Gatlin, the once-barred American sprinter who has been another target of athletes’ criticism since his return, they are being called out even though the system in place gives them every right to resume competing.  King said Monday night that she believed any athlete with a doping offense — including Gatlin — should not be allowed to compete. The national governing body for track and field, U.S.A. Track & Field, issued a statement on Tuesday rejecting that notion.  “The WADA code indicates that when an individual has completed their suspension, they are eligible to re-engage in the sport,” the statement said. “The Amateur Sports Act stipulates that if an athlete is eligible to compete, they cannot be prevented from being on a national team. So in the United States, it is a matter of law. If you are not under a ban, regardless of what you may have served in the past, you are fully eligible to be on the team.”  Still, Nelson defended the right of athletes to criticize once-barred competitors.  “It’s not undermining the system,” he said. “It highlights a major flaw in the system. Ms. King could have lost out on an Olympic gold medal future had the events turned out differently yesterday, and she would have had to accept the fact that a known doper beat her. Where’s the spirit of Olympism in that outcome?”  A version of this article appears in print on August 10, 2016, on page A1 of the New York edition with the headline: In Rio Pool, Disdain for Dopers Is Bubbling Over. Order Reprints| Today's Paper|Subscribe
Swimmers at the Rio Games who once served suspensions for doping have been openly vilified by their rivals, creating plenty of awkwardness.