Ruti Aga said that a positive drug test after winning a half marathon in China was due to a prescription for treatment of a knee injury. Upon investigation, anti-doping regulators determined the clinic listed wasn’t real, and the person who signed it was a family member who wasn’t a registered doctor.

The 32-year-old Ethiopian marathoner has now been banned for six years, the Athletics Integrity Unit announced Thursday , after testing positive for methylprednisolone following her win at the Meishan Renshou Half Marathon on March 15. The drug is prohibited in competition under World Anti-Doping Agency rules .

Aga, the winner of the 2019 Tokyo Marathon and one of the world’s elite women’s distance runners, said in an April interview with investigators that she’d been given the medication in Ethiopia to treat knee pain, and turned over a prescription in May.

However, AIU officials found the person who signed the prescription was a relative and not recognized as a physician by the country’s medical authority.…