Former University of Michigan track star Nick Willis might see his 2008 Olympics finish moved up again without taking a step.
Kenyan Asbel Kiprop, the 1,500-meter gold medalist in Beijing, has tested positive for a banned substance, according to reports.
Kiprop gained the gold medal in 2009 when Bahrain's Rashid Ramzi failed a drug test. Willis, competing for New Zealand, finished third but was moved up to silver medalist.
Kiprop, though, denies the doping claims, the BBC reports.
"I have been at the forefront of the fight against doping in Kenya - a fight I strongly believe in and support," said Kiprop, who has run the fifth fastest 1500 of all time.