Decision in Caster Semenya case delayed until end of April

South African runner Caster Semenya will have to wait until the end of April to get a verdict in her challenge of IAAF rules seeking to control naturally high testosterone levels in female athletes.

The delay announced Thursday by the Court of Arbitration for Sport to allow more legal debate creates confusion for Semenya and other runners affected by the proposed rules who are preparing for the world championships in September.

The court had last month set a target of next Tuesday for a verdict — six months and one day before Semenya is due to begin defending her 800-metre title at the worlds in Doha, Qatar.

The IAAF's intended rules require female runners to medically control their natural testosterone for at least six months before running in top-tier middle-distance races.

The new target for a verdict is just five months before the track worlds open.

Can scientific data prove testosterone advantage?

The complex case was the subject of an unprecedented five-day appeal hearing last month in Lausanne, Switzerland.

"The parties have filed additional submissions and materials and agreed to postpone (the verdict)," the court said in a statement .

The decision, to be made by three CAS judges, will decide how athletes with what the IAAF refers to as "differences of sexual development (DSD)" are treated.

Semenya's lawyers have said the rules discriminate against her and her "genetic gift." The IAAF argued it is striving for ensure fairness on the track because DSD athletes have testosterone levels in the male range, giving them an unfair advantage.

The case will likely hinge on whether the IAAF can prove with scientific data that testosterone gives the DSD runners a significant advantage.

If Semenya's appeal is dismissed, she could switch to running the 5,000 meters without being required to medicate.