Double amputee Oscar Pistorius must run the first leg for South Africa if he is to take part in the 4x400m relay at the world championships, athletics governing body said on Friday.
"This person is a particular case," IAAF head Lamine Diack said of the athlete who runs with carbon fibre prosthetic blades in place of his lower legs, which were amputated before he was a year old due to a congenital condition.
"The only thing we said to the South African federation is that if he wants to run in the relay, he must run the first leg to avoid danger to other athletes."
The 24-year-old will make history in Daegu when he becomes the first amputee athlete to compete at the world championships.
Pistorius first competed against able-bodied athletes in 2007 but the IAAF then amended its rules to ban the use of "any technical device that incorporates springs, wheels or any other element that provides a user with an advantage over another athlete not using such a device".
In the following year the world governing body said scientific research had shown Pistorius enjoyed an advantage over able-bodied athletes and banned him from competitions held under their rules.
However, the decision was over-ruled by the Court of Arbitration for Sport, making Pistorius eligible for the 2008 Beijing Olympics although he was unable to qualify for the South African team, winning gold medals instead in the Paralympic 100, 200 and 400 metres.
