The CAS, ruling on the case after the Badminton World Federation (BWF) appealed the decision of its Doping Hearing Panel not to sanction Kune, said the reigning African champion failed to prove a positive test recorded at the 2019 All-African Championship was the result of deliberate spiking.

Kune has been formally disqualified from the tournament, where she claimed the women's singles silver medal, following the CAS ruling.

The 27-year-old, who carried her country's flag at the Opening Ceremony of the 2016 Olympics in Rio de Janeiro, is banned from the sport until December 15, 2022.

In a statement, the CAS said Kune "had failed to establish on the balance of probabilities how the prohibited substance entered the sample" and rejected the "sabotage" theory she had presented to the panel.

"On the basis of the evidence put forward by the parties and by an independent expert, the CAS panel found the athlete’s assertion of intentional spiking during the 2019 African Badminton World Championships devoid of supporting evidence thereby falling short of a cogent explanation as to how the prohibited substance entered her body," the CAS said.

Kune had been stripped of the silver medal at the All-African Championship, where she lost the women's singles final to Nigeria's Dorcas Ajoke Adesokan.

She had not been suspended due the BWF Doping Hearing Panel determining that she "bore no fault or negligence".

The BWF appealed the decision not to sanction Kune, claiming it "touches upon the interpretation of fundamental principles of the World Anti-Doping Code and the anti-doping regulations".