Beijing: Kenya`s runaway success at the world athletics championships has been punctured by awkward questions after two of their athletes became the tournament`s first to fail drugs tests.
The African nation has opened up a sizeable lead on the medals table but celebrations will be muted after the two suspensions were announced late on Tuesday.
Joyce Zakary`s Kenyan record of 50.71sec in the women`s 400m heats now carries a big question mark after she failed a pre-competition test, along with hurdler Koki Manunga.
The championships` first doping cases follow a build-up dominated by lurid drugs allegations, with Kenya one of the countries in the firing line.
Leaked results cited by German broadcaster ARD and Britain`s Sunday Times newspaper claimed that more than 800 athletes, including 18 Kenyans, had "suspicious blood test results" between 2001 and 2012.
Kenyan officials were already investigating an alarming spike in doping cases in the country after more than 30 athletes failed tests in the past two years.
"It is not good for the Kenyan team because leading into these championships there were a lot of allegations in the situation around blood doping -- and a lot of fingers pointed at Kenya," said former athlete and BBC commentator Steve Cram.
Kenya was rocked this year when marathon star Rita Jeptoo was banned for two years after being caught doping with the banned blood-boosting hormone EPO.
Jeptoo is the biggest name in Kenyan sports to have been caught, and the bust has been a major trauma for a country that idolises its medal-winning runners.Kenyan performances have lit up Beijing, including world record-holder David Rudisha`s superb 800m win after he battled back from two years of injury problems.
Late on Tuesday, Julius Yego hurled his javelin a massive 92.72 metres -- the longest throw in 14 years -- to become Kenya`s first javelin world champion.
"It`s a shame for them," said Yego, when asked about Zakary and Manunga. "In sport you win clean so it`s a shame for them. I can`t make any more comment on that."
Hyvin Kiyeng Jepkemoi, who won the women`s 3000m steeplechase title shortly after Yego`s monster throw, said she was shocked at the failed doping tests.
"I think that`s an individual thing, it`s not everybody," Jepkemoi said. "I`m totally shocked.
"I know I`m clean but I`m not happy about it."
Kenyan journalist Evelyn Watta told the Guardian that Kenyan authorities were taking doping seriously after previously dismissing the problem.
"Initially when our athletes were first linked with doping in 2011 and 2012 the initial reaction was no, it`s a lie -- there is no doping in Kenya," she said.
"But now we are more mature. And there`s a sense of if there`s something wrong, Athletics Kenya and the Kenyan government need to make sure the bad apples are removed. It is not denial, denial, denial."
Athletics Kenya has said it was investigating the cases of Zakary and Manunga and promised "follow-up action" against the two offenders.