Swimming is “not a clean sport” and needs an athletics-style investigation to ensure fair racing at Rio 2016, according to a leading coach.
Briton Jon Rudd guided Plymouth-based Lithuanian Ruta Meilutyte to Olympic gold at London 2012.
Meilutyte’s main rival, Yuliya Efimova, faces a possible lifetime ban after testing positive for a banned substance for the second time in her career.
“There’s no doubt in my mind, we’re not a clean sport,” Rudd told BBC Sport.
“It was a shock the first time Yuliya tested positive and it’s disappointing a talented athlete has chosen this route to try and achieve her ambitions.”
Russian world champion Efimova is just one high-profile example of a much bigger problem for Russian sport.
From the beginning of 2010 to the end of 2015 a total of 27 swimmers tested positive for banned substances and served bans.