In November, Kenyan Olympic gold medalist Asbel Kiprop heard from a doping control officer who told him to expect a visit the next day. Advance notice for urine tests is prohibited under World Anti-Doping Agency rules, but Kiprop said he didn’t think anything of it because he had been warned about such tests before.

So he also didn’t pay any mind to the fact that the official testing him asked for money after he gave them his urine sample.

“I thought he wanted small money, maybe for tea,” the athlete told BBC Sport this week. “I thought in my mind maybe he wanted tea, or to fuel the car.”

Kiprop complied — and left the room to send the officer money over his phone. He said it was normal “generosity” to give a small gift, especially because he knew the tester personally. He didn't consider that it could have been interpreted as a bribe.

Then the athlete’s urine sample came back positive for EPO, a blood-boosting agent that violates international doping rules.

Despite the positive test, the 1,500-meter runner insists he never doped. Instead, he speculates that the officer must have been expecting a much larger sum from him and so tampered with his sample.

“The minute I went into my room to send them the money, probably something happened there on the table to my urine sample,” he said. “It is not beyond my suspicion that my sample turned positive because I might have remitted less money than I was expected to remit.”

The out-of-competition test took place in November, and in February, he was notified that he had failed it. The Athletics Integrity Unit, which handles all doping cases in international athletics, confirmed that his sample tested positive for performance-enhancing drugs and insists that there was no tampering with the sample. The group also said that Kiprop should not have been given advance notice of the test, and said that it was “extremely disappointing” that the tester broke the rules and gave Kiprop a heads-up, but that it does not disqualify his positive sample.

In March, the 28-year-old was charged with violating anti-doping regulations. His case now sits with the International Association of Athletics Federations. A disciplinary tribunal could ban him for competing for up to four years if they determine he is guilty of doping.

The Kenyan athlete is one of the fastest 1,500-meter runners in history. In the 2008 Olympics in Beijing, he came in second but ended up earning a gold medal when Bahraini runner Rashid Ramzi failed a doping test.

This is just the latest doping scandal that has embroiled Kenya's international athletes in recent years. Ahead of the 2016 Olympics in Rio de Janeiro, Kenya was almost banned from taking part because the World Anti-Doping Agency found the country to be noncompliant after missing two separate deadlines to improve its doping policies. At the time, about 40 Kenyan athletes had failed drug tests since 2012.

Then, at the games themselves, one Kenyan sprint coach posed as an athlete and provided a urine sample on that runner's behalf. And Kenya's athletics manager, Michael Rotich, was sent home early from the games after he was accused of trying to find a way to provide athletes with early warnings about drug tests.

Still, Kiprop claims he is clean and that he even supports jail time for dopers, and that now he himself is “suffering like a prisoner.”

“I’m being put in the category of the dopers,” he said. “Good people, athletes, my competitors and opponents, they think I have been racing with them and cheating.”