The man billed as the world's fastest on no legs will attempt to take two giant steps towards the Beijing Olympic Games this weekend.

Oscar Pistorius is a double amputee who runs wearing carbon fibre blades. It has been claimed they give him artificial help and an unfair advantage. The world athletics body, the IAAF, banned him initially, but are now re-investigating his blades, "Cheetahs" to which the South African has attached a strip of sole from a pair of Nike running spikes.

The IAAF will be given food for thought this weekend. The Paralympic 200 metres gold medallist and world record-holder at 100, 200 and 400m, runs in the B 400m at the Rome Golden League on Friday night, and then against one of the hottest international fields assembled so far this year, at Sheffield on Sunday afternoon.

The one-lap race, in the Norwich Union British Grand Prix at the Don Valley Stadium, includes Olympic champion Jeremy Wariner, his fellow American and former Olympic relay gold medallist Darold Williamson, the Australian Commonwealth 400m gold medallist John Steffensen, and former Olympic one-lap hurdles champion Angelo Taylor.

Pistorius, born minus fibulas (the outer bone between knee and ankle) was 11 months old when his legs were amputated below the knee. He says his prostheses have been around, unchanged, for 14 years. Each foot is made from multiple layers of carbon fibre and weigh around 1.8 kilos.

"It's a passive foot," he said. "The energy that you give to compress the prosthetic isn't the same as what it gives out, so it definitely does not give me an unfair advantage.

"If they ever find evidence, then I would stop running. It's not something I would want to compete at if I knew I had an unfair advantage."