American backstroke star Ryan Murphy has said that doping remains a huge problem in swimming and he wonders if all his competitors are clean. Murphy’s comments came after he lost for the second time this week to Russia’s Evgeny Rylov, who took gold in the 200m backstroke. Rylov, who has long been one of the world’s top backstrokers, said he has always been tested and was a supporter of clean sport. Murphy said he was not accusing Rylov of wrongdoing.