Aug 19, 2009, 17:37 GMT
Berlin - Olympic champion LaShawn Merritt stormed into the 400 metres final at the world athletics championships on Wednesday with the fastest time run this year over the distance.
Merritt clocked 44.37 seconds in his semi-finals as he advanced along with fellow-American two-time defending world champion Jeremy Wariner, who won his race in 44.69 seconds.
Due to run later in the 200m semi-finals was Jamaican sensation Usain Bolt, the triple Olympic champion who on Sunday lowered the 100m world record to 9.58 seconds in the final.
The four medal events were the men's 1,500m and discus as well as the women's 800m and 100m hurdles. The decathlon also continued to its halfway mark.
The women's 800m was overshadowed by controversy as the ruling body IAAF confirmed it has requested a gender varification test on Caster Semenya of South Africa, who burst onto the scene with a world leading 1 minute 56.73 three weeks ago.
Doubts were raised because of her masculine physique and Davies said a complex process of medical examinations has started, with results expected within the next weeks.
'We don't have any conclusive evidence that she should not be allowed to run,' IAAF spokesman Nick Davies told reporters.
'We are waiting for the report ... We simply ran out of time,' said Davies, adding it would be nonetheless 'terribly wrong to withdraw the athlete.'
Davies said that even if Semenya is found out not to be a woman she could not simply be stripped of a gold if she succeeded on Wednesday.
'It is no straightforward procedure, it is legally complex. If she always though she was a woman it would be no cheating,' Davies said.
Earlier in the day, three-time world champion Franka Dietzsch of Germany failed to make the discus final in her 10th appearance at the world while Ethiopian distance running star Tirunseh Dibaba did not compete in the 5,000m heats due to injury.
In addition, Cuban Olympic champion Dayron Robles stated a thigh injury which made him unsure whether he could continue in the 110m beyond the heats through which he barely advanced.
'I have trouble with my left leg. I can't say whether I can run tomorrow or not. I will work hard with my doctors. We will then see what is possible,' the world record holder said.
But he added: 'I promised Fidel Castro to bring home the gold medal for him. And I want to keep my promise.'
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