SYDNEY, Australia (AP) _ Marie-Jose Perec, the mystery woman of the Sydney Olympics, now has completely disappeared.

Perec, two-time defending champion in the 400 meters and a potential threat to favorite Cathy Freeman in the 400 at the Sydney Games, left the country one day before first-round heats in the event. She said she was menaced in her hotel room.

French Olympic officials said Perec left for Singapore.

``She hasn't been officially excluded from the team,'' said Michel Vial, head of the French delegation. ``The team still hopes she can come to compete in Sydney. At this point, being in Singapore, it is very improbable that she will compete. But she is still officially entered. Things are possible with planes.''

Vial said nobody in the French delegation had spoken to Perec in three or four days.

``It's a shame that she was not able to become part of the delegation at our training camp or at the Olympic village,'' he said. ``Maybe she made a bad decision by not staying in the village, where she would have been more secure.''

Denise Kaigler, spokeswoman for Perec's chief sponsor, Reebok, said earlier that Perec would not compete in the games. She later said it was possible Perec would compete.

``Marie-Jose has been under a great deal of pressure and yesterday afternoon she was harassed in her hotel room by an unidentified man who forced his way into her room and threatened her.''

Perec, who became only the second woman in Olympic history to sweep the 200 and 400 when she accomplished that feat in Atlanta, also was the 400-meter champion at the 1992 Barcelona Olympics.

Freeman has not lost at 400 meters in more than three years but has lost seven of her nine career races against Perec. She was not talking to reporters Thursday. But Australian track and field coach Chris Wardlaw said Perec probably wasn't ready to run.

``I think if she's not here she obviously wasn't in shape, so it wouldn't have been a great race anyway,'' Wardlaw said. ``She's the athlete of the decade in the `90s, a truly great athlete, and obviously in her mind she wasn't going to be able to compete up to that level.''

Perec, nicknamed ``The Gazelle'' because of her fluid, long-legged running style, won the 1996 Atlanta Games gold in 48.25 seconds _ an Olympic record. But she has not won a 400-meter race since then.

Before her one 400-meter race this summer, in which she placed third, Perec said she realized a comeback would be difficult.

``You don't stop running the 400 for four years without experiencing a certain amount of apprehension. I have to admit I'm scared,'' she said. ``After the Barcelona Olympics in 1992, I went two years without running the 400. I still remember my return in New York in 1995. It was hard. But now I'm expecting the worst.''

Perec, 32, had been a mystery woman in Sydney, where she refused to train with the French team and hid from reporters. Her only public appearance was at the Sydney Airport, where she sprinted past cameramen.

She has been so reclusive that the Australian media labeled her the ``Greta Garbo of athletics.''

Perec has been tormented by Epstein Barr syndrome, a rare virus that causes chronic fatigue, and dropped out of three races this summer in Europe that would have pitted her against Freeman.

Perec's only public comments have come on her web site. On Tuesday, she wrote that her training was going well but that she was scared.

``The games have hardly begun and already I wish they would end because I'm so scared,'' she wrote. ``I simply have to make sure my training place stays secret. That's the main thing, is to stay relaxed.''