Ethiopian marathon runner Ruti Aga has been handed a six-year ban after she attempted to explain a positive test for a banned substance using a prescription from a non-existent clinic, issued by a doctor who turned out to be a family member.

Aga, who won the 2019 Tokyo Marathon, tested positive for methylprednisolone after winning a half marathon in China in March.

She received a two-year ban for testing positive for the prohibited steroid - used to reduce inflammation and classed as performance enhancing by the World Anti-Doping Agency (Wada).

The 32-year-old was given a further four-year ban for tampering with evidence and misleading investigators during an interview.

"Aga attributed her positive test to treatment for a knee injury, submitting a prescription from a clinic that did not exist, issued by a 'doctor' who turned out to be a family member with no medical registration with the relevant authority," the Athletics Integrity Unit (AIU) said on Thursday.

"When questioned, the family member claimed to have used an old prescription pad from a former workplace. But that clinic confirmed the individual had never worked there and the prescription was not theirs."

Aga, who has finished second three times at World Marathon Majors, has been provisionally suspended since 10 September and the ban will run from that date.