LONDON, England (AFP) — South African double amputee Oscar Pistorius is free to run in any lane in the 4x400m Olympic relay, IAAF president Lamine Diack said yesterday, changing his previous stance on the issue.

At last year's World Championships in South Korea, the IAAF said Pistorius would have to run the first leg to "avoid danger" to other runners before handing over the baton to the second runner, who then breaks the lane order.

Pistorius, who runs with carbon fibre prosthetic running blades, ran the first leg of the heats in Daegu in 2011 but was left out of the final line-up as South Africa won silver.

But speaking ahead of the start of athletics events later this week at the London Olympics, the IAAF chief said although the first leg was a better option, it was up to the South African federation to decide.

"It is better that he runs the first leg because in the first leg you are in lane," said Diack. "There is no contact until you transmit the baton."

He pointed out that Pistorius ran the third leg of the relay in the recent African championships in Benin.

"We cannot tell them 'you have to put him in this place'," Diack told reporters following an IAAF council meeting in London, saying it was no problem for the IAAF.

Pistorius will become the first double amputee athlete to compete at an able-bodied Olympics when he lines up in the men's 400m. He will also race in the 4x400m relay.

The 25-year-old, known as 'Blade Runner' because of his blades, has not been universally welcome with some observers believing he has an unfair advantage.

Meanwhile, the IAAF said it was confident empty seats would not be an issue at the Olympic Stadium after organisers faced criticism over the banks of empty seats seen at various venues at the Games.

"LOCOG is speaking to all the international federations because the issue is about accredited areas. And we're happy to hear from LOCOG," communications director Nick Davies told AFP.

"Seb (Coe, the London 2012 chairman) is one of us from athletics. Seb has basically asked us to consider ways we can help. The first way you can help of course is making everyone who's got a pass goes to the seats, which is the ideal situation."

"We're not too worried.... We are in close contact with Seb and LOCOG and we'll do whatever we can to help."