'Halkia tested positive for drugs,' one official told Reuters on condition of anonymity, confirming one of the biggest doping cases since the start of the Aug 8-24 Olympics.

The test was taken around Aug 10 when Halkia was in Japan with the rest of Greece's track and field team to prepare for the Games, he said. The athletics events at the Games kicked off only on Friday, one week after the opening ceremony.

Halkia denied she had taken performance enhancing drugs.

'I can't believe it ... The first thing I thought of doing was to give all the nutritional supplements I have consumed, my vitamins, for testing,' Halkia told Greek reporters in Beijing.

The 29-year-old Halkia was a surprise winner in the 400 metres hurdles at the 2004 Athens Olympics and has rarely raced since then. The first round of the women's 400 metres hurdles is scheduled for Sunday evening, with the final on Aug 20.

The Greek Olympic Committee said in a brief statement an athlete had been suspended after a first sample had tested positive.

It did not name the athlete but said the person had left the Olympic Village pending the results of tests on a second sample.

Greek woes
Halkia is the latest in a long list of Greek athletes who have failed tests over the past few months, including 11 weightlifters, a swimmer and a rower.

Sprinter Tassos Gousis had earlier been sent home from the training camp in Japan after he failed a Greek doping agency test days before he was due to compete.

Katerina Thanou, a 100 metres silver medallist in Sydney in 2000, had also been barred from competing in Beijing because of her involvement in a doping scandal four years ago, the International Olympic Committee (IOC) said a week ago.

On Friday, the IOC said there would be far fewer positive drugs tests in Beijing than initially expected as officials were catching up with cheats.

The IOC had said previously it expected some 30-40 positive cases out of a planned 4,500 tests, the most conducted at an Olympics.

In Athens four years ago, there were a total of 26 cases of positive tests or other anti-doping rule violations such as refusal to provide a sample or missed drugs controls from some 3,300 tests.

But more intensive pre-Games testing by international sports federations, national Olympic committees and the World Anti-Doping Agency had yielded results this time, said the IOC.

Before Friday, only three athletes had tested positive out of about 2,200 tests after six days of competition, it said.

The Greek Olympic Committee, alarmed by the number of postive cases, had pledged before the Games to test every team member at least twice to avoid more embarrassment. -- REUTERS