The Court of Arbitration for Sport, meeting in Lausanne, Switzerland, upheld Pistorius' appeal of an IAAF Council ruling that he would be unfair competition.

A double amputee, Pistorius has walked on prosthetics for years and uses Cheetah Flex-Foot prosthetic feet for running.

In January, following a series of tests, the IAAF Council declared the "Cheetah" prosthetics constitute a "technical device" which, under IAAF rules, gives the user an advantage and therefore Pistorius was ineligible to compete.

The runner appealed and the court of arbitration ruled in his favor, deciding it was not proven that Pistorius got an advantage from the equipment and immediately restored his eligibility.