Former 1500 metres world champion Elijah Manangoi has been provisionally suspended over an alleged whereabouts failure.
The 27-year-old Kenyan won gold at the 2017 World Championships in London, having claimed silver in Beijing two years earlier.
He was one of four athletes from the African country who the Athletics Integrity Unit announced on Thursday had been suspended or provisionally suspended pending a full hearing.
Patrick Siele was provisionally suspended after he was alleged to have evaded, refused or failed to submit for a sample collection.
Mercy Kibarus was banned for eight years after testing positive for an anabolic steroid, a second doping offence within a 10-year time frame.
Kenneth Kipkemoi was suspended for two years after testing positive for terbutaline.
