American backstroke swimmer Ryan Murphy alleged Friday that doping remains a problem in the sport after he lost twice to swimmers on the Russian Olympic Committee.

       “It is a huge mental drain on me throughout the year to know that I’m swimming in a race that’s probably not clean,” said Murphy. “It frustrates me, but I have to swim the field that’s next to me.”

       Anadolu Agency via Getty Images

       Evgeny Rylov (R) and Kliment Kolesnikov (L) of ROC celebrate after winning the gold and silver medals in the final of the men's 100m backstroke swimming during the 2020 Olympic Games in Tokyo, July 27, 2021.

       Murphy, who won gold in Rio de Janeiro 2016 in the 100- and 200-meter backstroke, lost to swimmer Evgeny Rylov in the 200-meter and placed third behind Rylov and another swimmer, Kliment Kolesnikov, in the 100-meter backstroke this year. Both are part of the Russian Olympic Committee team.

       The defeat marked the first time since 1992 that an American hadn't won in the men's backstroke competition.

       Valery Sharifulin/TASS via Newscom

       An ROC flag is pictured during an award ceremony at the 2020 Summer Olympic Games in Tokyo, July 28, 2021.

       “To be clear, my intention is not to make any allegations here. Congratulations to Evgeny,” Murphy added. "I do believe there is doping in swimming.”

       After the 2014 winter Olympic Games in Sochi, Russia, whistleblowers uncovered a massive state-sponsored doping program. In 2019, the World Anti-Doping Agency banned Russia from officially sending any athletes to an international sports competition until December 2022, but the International Olympic Committee made the controversial decision to allow some Russian athletes to compete in Tokyo under the moniker Russian Olympic Committee (ROC) after testing showed they were clean.

       Maddie Meyer/Getty Images

       Silver medalist Ryan Murphy of the US, gold medalist Evgeny Rylov of Team ROC and bronze medalist Luke Greenbank of Great Britain pose during the medal ceremony for the Men's 200m Backstroke Final at the 2020 Olympic Games in Tokyo, July 30, 2021.

       Rylov denied being a part of any doping schemes and said Friday that he had been tested and swam a clean race.

       "From the bottom of my heart, I am for clean sport. I’ve devoted my entire life to this sport... Ryan didn’t accuse me of anything, so I’d rather not comment,” he said during a press conference on Friday.

       MORE: Why Russian athletes are competing under the ROC at Olympics

       As of Friday, the ROC team has won 34 combined medals, including 10 gold, the third highest of all competing nations. None of those medals will be recorded in Olympic records as Russian wins.