Caster Semenya Files Case to Challenge Rules That Could Force Her to Reduce Her Testosterone Levels

South Africa middle-distance runner Caster Semenya on Monday arrived at the Court of Arbitration for Sport (CAS) in Lausanne, Switzerland for a hearing of a case she has filed against the International Association of Athletics Federations (IAAF).

The 800 meters Olympic champion is challenging the proposed rules by IAAF that could force her to lower her testosterone levels.

The 28-year-old has the backing of the South African government which argues that the proposed rules specifically target Semenya, terming them a "gross violation of her human rights."

If IAAF wins the case, "hyperandrogenic" athletes or those with "differences of sexual development" (DSD) would be compelled to take drugs to lower their testosterone levels below a prescribed amount for them to be allowed to continue competing.

The rules were introduced last year but have not taken effect due to the week-long hearing that has kicked off on Monday. A ruling on the case will be made in March.

"Today is a very, very important day. The regulations that we are introducing are there to protect the sanctity of fair and open competition," IAAF President Sebastian Coe said on arriving at the court.

Last week, the 800m World Champion issued a statement declaring that she's "unquestionably a woman".