LAUSANNE, Switzerland -- Sport's highest court said Monday it will hear a case concerning alleged doping by Spanish hurdler Josephine Onyia.

The Court of Arbitration for Sport said the International Association of Athletics Federations wants Onyia banned for two years after she twice returned positive tests in post-race doping controls last year.

The IAAF is appealing against the Spanish Athletics Federation's refusal to punish the 22-year-old runner in both cases. The federation disputes the test results.

Onyia tested positive for an unnamed stimulant after racing at Lausanne last Sept. 2, and for a banned anabolic agent _ believed to be clenbuterol _ after winning the 100-metre hurdles at the World Athletics Final in Stuttgart, Germany, on Sept. 13.

The court said it hoped to give a ruling within four months.

Clenbuterol is used as a weight-loss drug which builds muscle while burning fat. It is commonly given to horses to treat respiratory problems.

Onyia was born in Nigeria but obtained Spanish citizenship in 2007. She won the 100 hurdles in last year's Golden League meetings in Oslo and Berlin.