Kenyan sprinter Mark Otieno Odhiambo has been provisionally suspended for failing a drugs test during the Tokyo Olympics.
The 28-year-old had been due to compete in the heats of the men's 100m on Saturday but returned an adverse analytical finding for anabolic androgenic steroid.
According to a Kenya's Chef de mission in Tokyo Waithaka Kioni: "He has however denied any knowledge of the violation and has subsequently requested a re-analysis of his B urine sample."
The test was carried out on 28 July while the athlete was at the Olympic village in Tokyo, before that he had been at a training camp in Japan between 15 and 24 July.
Otieno Odhiambo competed at the 2017 World Championships and the 2018 Commonwealth Games.
He is the second African sprinter to be suspended for failing a drugs test during the Tokyo Olympics after Nigeria's Blessing Okagbare.
Kioni insisted that the sports officials and governing bodies in Kenya are determined to continue their battle against doping.
"These are things that are maybe are avoidable this is why are continuously continue liaising with sports federations and ADAK so we continue to give education on anti-doping to our athletes," he told BBC Sport Africa.
"But you can only go so far but it is not that athletes are not aware and that is why we are assuming he is innocent until we get re-analysis of B sample.
"I chatted with him this afternoon and he tells me he cannot recollect consuming anything that would yield those kind of results.
"What concerns me is Kenya has already been on the red list category and we were hoping of we will get out of that category but an incident like this may just interfere with that progression towards that - doesn't help the case"