The 21-year-old medal prospect competes in the two-day National Championships at Nelson Mandela University in Indian Ocean city Port Elizabeth from Friday.

South African Olympic officials have insisted that athletes reach qualifying times at least twice before being selected for the Games, as they are aware of claims that past Olympic teams contained no-hopers.

Semenya bettered the one minute 59.90s qualifying time last year in South Korea when finishing second behind Russian Mariya Savinova in her world title defence and must do so again to seal a first Games appearance.

Targets

Last year, the hopeful changed coaches, replacing Michael Seme with former Olympic 800m gold medalist Maria Mutola from neighbouring Mozambique, with the pair targeting a sub-two-minute run this weekend.

Mutola, who struck gold at the 2000 Sydney Games and represented her country at football before teaming up with Semenya, said: "We are looking for anything under two minutes this weekend.

"If we go to Europe with anything under two minutes it would be a good thing but two-something could be a problem confidence wise," the 39-year-old coach added.

Tactics

Semenya backed her trainer, saying: "I am capable of running below two minutes so I will try to reach that goal on Saturday provided the weather is good," speaking of the venue in the 'Windy City'.

"Maria has been really good for me. She has not changed much in my training programme, but is concentrating more on my race tactics and some technique work."

The South African runner endured a difficult three years after her 2009 world title in Berlin, undergoing gender tests that side-lined her for 11 months as well as being hampered by a back injury.

Semenya is among a strong group considered as the best South African athletics medal prospects, alongside 400-metre hurdler LJ van Zyl, women's javelin thrower Sunette Viljoen and a 4x400m relay team including Van Zyl and double-amputee Oscar Pistorius.

Van Zyl is so far the only athlete who has clinched a place in the London-bound team and Pistorius needs one more sub-45.30s race to book a place as a 400m runner.