Athletics South Africa (ASA) have issued a rebuke of the International Association of Athletics Federations (IAAF) and say the body failed to prove their case in the appeal hearing of double Olympic champion Caster Semenya. ASA also claim the IAAF have sought to further amend regulations that would limit the testosterone levels of athletes classed as having differences in sexual development (DSDs). It is that reason that ASA say is the cause of the delay in the announcement of a verdict by the Court of Arbitration for Sport (CAS) that had been postponed from the original deadline of March 26 to the end of April. Under the new rules, athletes classed as having DSDs would have to reduce their blood testosterone level to below five (5) nmol/L for a continuous period of six months before they can compete. They must then maintain it below that level continuously. The IAAF did not immediately respond to a request for comment. CAS ruled in favor of Indian sprinter Dutee Chand in a similar appeal in 2015, stating that the IAAF had failed to prove a link between higher levels of testosterone and athletic performance, and that the evidence was needed to reach a verdict. The IAAF claim they now have the scientific proof of unfair advantage for DSD athletes and that this was presented to CAS at Semenya's five-day hearing in February, but ASA believe they fell short again. "The IAAF was required to place empirical evidence... to establish that the naturally occurring testosterone levels of athletes targeted by the DSD Regulations confer a significant performance advantage... which would justify limiting their eligibility to compete in the manner that the IAAF seeks to do through the DSD Regulations," an ASA statement said on Friday. "The IAAF has again failed to do so in the proceedings before CAS, and has sought rather to contend that female athletes targeted by the DSD Regulations are in fact "biologically male". "The analyses relied on by the IAAF do (sic) not show a meaningful relationship between testosterone and performance." ASA have also claimed that the IAAF have sought to amend their regulations, without going into details of what the changes are. "The delay in handing down the CAS award is entirely due to the IAAF seeking to amend the regulations post the CAS hearing. This necessitated a further exchange of written argument between the parties," the statement said. — Reuters