The International Association of Athletics Federation has confirmed that Oscar Pistorius must run the first leg if he is to participate in the 4x400m relay at the World Championships.
Pistorius, who will make history in South Korea by becoming the first amputee athlete to compete in the able-bodied competition, is already running in the individual 400m.
However, due to his carbon fibre prosthetic blades in place of his lower legs, the IAAF have insisted that he opens the race for South Africa on safety grounds.
"He must run the first leg to avoid danger to other athletes," said IAAF head Lamine Diack.
The meeting in Daegu starts tomorrow.