The International Association of Athletics Federations (IAAF) has announced that it will postpone the implementation of its new policies on athletes with high testosterone levels for five months as it awaits the outcome of South African track athlete, Caster Semenya's challenge of its legality.

The rule, which the IAAF planned to begin enforcing on November 1, would force women athletes with "higher testosterone" to chemically lower their levels or compete with men.

Semenya, with the backing of Athletics South Africa (ASA) has challenged the policy at the Court of Arbitration for Sports, stating that the rules have a "discriminatory effect on female athletes like Semenya. The federation also stated that it believes "the medical data relied upon by the IAAF is flawed," reports BBC Sport.

Despite Semenya and the ASA's challenge the IAAF says it feels "very confident of the legal, scientific, and ethical bases for the regulations, and therefore fully expects the Court of Arbitration for Sport to reject these challenges."

The federations says it will hold off on enforcing the rules until the challenge is upheld in court. "The IAAF also understands that all affected athletes need certainty on the point as soon as possible," said IAAF president Sebastian Coe, according to Eye Witness News South Africa.

"Therefore, in exchange for Ms Semenya and the ASA agreeing to an expedited timetable, the IAAF has agreed not to enforce the regulations against any athlete unless and until they are upheld in the CAS award, which is expected on or before 26 March 2019."

Though the ASA says it is "pleased" with the "suspension" of the decision, the delay means that if the testosterone rule is to go into effect next year, athletes such as Semenya may not be able to compete for at least half of 2019, since the policy stipulates that female athletes must keep their testosterone levels below the prescribed amount "for at least six months prior to competing."

"It is not fair," said 27-year-old Semenya of the proposed rule back in June. "I just want to run naturally, the way I was born."