As accusations of Russian doping surfaced at the Tokyo Olympics pool, the head of the United States Anti-Doping Agency (USADA) spoke out on Saturday coming to the defense of American swimmer Ryan Murphy for suggesting some of his rivals were drug cheats.

After losing the second of his 2016 Rio Olympic backstroke titles to Russian Evgeny Rylov on Friday, an unhappy Murphy hinted doping had played a part in his demise.

Murphy later walked back his comments saying they were not directed specifically at his Russian rivals but at the sport, which he said still has a big doping problem.