New Zealand runner Zane Robertson has repeated his claims that doping is being covered up in Kenya after breaking a 39-year-old national record in the 10,000m final at the Rio Olympics won by Britain's Mo Farah.
Robertson finished 12th in the race and bettered Dick Quax's record by more than eight seconds to clock 27 minutes 33.67 seconds as Farah recovered from a fall to retain his title from London.
Farah was tripped with 16 laps to go and fell to the track but he picked himself up and after a sizzling final lap won in 27:05.17.
But after the race Robertson repeated claims he had made about doping being hidden in Kenya.
"A lot of top guys are dirty," he said. "Names are hidden, positive tests are hidden for bribe money. It's a big problem," he said.
"I can only comment on what I know personally - I wouldn't make stuff up."
He refused to identify athletes because of legal concerns.
Robertson, who moved to Kenya when 17 to train and now lives in Ethiopia, said he believed more countries on the African continent were following Kenya's doping example.
"Surely in every East African country there must be some type of a problem because it's just the mentally there to join the game."
He has been outspoken in his criticism of doping in Kenyan athletics and said he had received evil looks from Kenyan athletes since arriving in the Olympic athletes' village.
But he said none of the three Kenyans in Saturday's race, silver medallist Paul Tanui, Bedan Muchiri and Geoffrey Kamworor, had shown him any animosity before it was run.
Tanui led Farah into the home straight on the final lap but the defending champion kicked clear and he had to settle for silver with Robertson's training partner Tamirat Tola from Ethiopia taking bronze.