Beijing has set up a sex determination lab to test female Olympic athletes suspected to be males.

Suspected athletes will be evaluated from their external appearances by experts and undergo blood tests to examine their sex hormones, genes and chromosomes for sex determination, according to Prof. Tian Qinjie of Peking Union Medical College Hospital.

Initial test results would be available in three days, while an official result takes seven days, he said.

The test aims to maintain fairness of the Games, and to rule out inaccurate test results.

Experts say test results for about one in 500 to 600 athletes are abnormal.

The tests are to be conducted at the Peking Union Medical College Hospital.

Polish runner Ewar Kobukkowska, who won a gold medal in the women's 4 X 100 meter relay and the bronze in the women's 100 meter sprint at the 1964 Summer Olympics in Tokyo, was the first athlete to be caught in a gender test after she failed the early form of a chromosome test in 1967.

She was found to have a rare genetic condition which gave her no advantage over other athletes, but was nonetheless banned from competing in the Olympics and professional sports.

At the 1996 Atlanta Olympics, eight athletes failed the tests but were all cleared by subsequent examinations.

In another case, Indian middle distance runner Santhi Soundarajan who won the silver medal in the 800 meters track event at the 2006 Asian Games in Doha, Qatar, failed the sex determination test and was stripped of her medal.

(Xinhua News Agency July 27, 2008)