LUCERNE, Switzerland: Double-amputee sprinter Oscar Pistorius fell short of the 400 metres qualifying time for the Olympics on Wednesday, though his lifetime best run could yet get him to Beijing in the relay.

The 21-year-old South African shrugged off the pre-race distraction of threatening legal action against the IAAF to finish third in his heat in 46.25 seconds. Although still outside the Olympic individual qualifying standard of 45.55, it was .11 faster than his previous best.

"I am so excited and so happy. I really enjoyed tonight," Pistorius said. "It was always going to be a very difficult task to achieve the individual time but there is still the hope of the relay."

The South Africa selectors will choose their team for Beijing Games by the weekend and can invite him to join the six-man squad for the relay.

To do so would defy a public request from the IAAF not to pick Pistorius, who runs using prosthetic limbs, because it believes he is a threat to his own and other athletes' safety. "I think it is the IAAF's last desperate attempt to try to get me not to qualify," Pistorius said.

His aspiration of attempting to qualify was made possible in May when he won an appeal at the Court of Arbitration for Sport to overturn an IAAF ban, which prevented him competing against able-bodied runners. On Wednesday, legal firm Dewey and LeBoeuf threatened a second legal action against the IAAF.

"We believe the IAAF is obligated to immediately advise the South African Federation and Olympic Committee that it has no objection to Mr Pistorius competing in the 4x400m relay at the Beijing Games," it said in a statement.

AP