The qualification criteria proposed by Athletics South Africa are tough, and if endorsed by the SA Sports Confederation and Olympic Committee, Pistorius will have to beat the A-qualifying time of 45.25 seconds in the 400m not just once, but twice.

ASA president James Evans said this week at least one of those times would have to be set after March 19, when the local track and field season gets into full swing.

Qualifying performances set at the World Championships in South Korea in August and September last year would be accepted, but nothing earlier.

Pistorius clocked 45.07s to get to the World Championships, but that was in July.

Evans believes Pistorius, having beaten the mark once already, can do so again.

"He would have to go backwards not to achieve that time again."

Pistorius competed in the first round and semifinals of the 400m at the World Championships, running times of 45.39s and 46.19s.

So far, only five South African athletes have achieved qualifying criteria, all at the World Champs - LJ van Zyl and Cornel Fredericks (both 400m hurdles), Caster Semenya (women's 800m), Sunette Viljoen (women's javelin) and Ruben Ramolefi (3000m steeplechase).

Evans stressed that even these five would have to repeat their A-qualifying efforts after March 19 - anyone failing to do so would not be considered for London.

In the past, some South African athletes posted good qualifying performances early in the Olympic year, but failed to replicate the performances at the Games.

Pistorius won his world championship silver as a member of the 4x400m relay team, which is likely to qualify as long as South Africa's time at the World Championships remains inside the world's top eight. If he fails to make it for the individual competition, he could have a chance if he remains one of South Africa's four - or five, at worst - fastest 400m runners.

Pistorius was South Africa's second-fastest over the distance last year.

Sascoc vowed to impose stringent selection criteria on Games hopefuls after the 2008 Beijing edition, where South Africa's biggest team in history returned with one medal - the nation's lowest Olympic tally in 100 years.