The Paris prosecutor's office said police were investigating the allegations made by a 25-year-old Australian woman that she was gang raped at the weekend.
She reported the incident after taking refuge in a restaurant in northern Paris, where she was attended to by emergency services, it said.
Australia's Olympic team chief, Anna Meares, told a press conference that the team was aware of the allegations.
"There's not a lot of detail and information that has come through, and what information we're passing on to our athletes, is that the security presence is really, really high," she said.
"We don't yet have any feedback from our athletes that they have felt unsafe. We are encouraging them, if they go out of the village, not to go out on their own, not to wear team uniform, just to wear plain clothes."
The Paris Olympics opening ceremony will take place along the Seine river on Friday amid high security.
There have been no direct threats from militant groups against the Games, French officials say, but petty crime and violence remain a concern for the thousands of tourists expected to descend on the French capital for the Games.
