Australia's Olympians could be subject to curfew and warned off vast areas of Rio de Janeiro following a number of violent robberies on athletes in the Games city.
The Australian Olympic Committee (AOC) has called on Rio Games organisers to mobilise their security force early, with chef de mission Kitty Chiller concerned by several recent incidents involving Australians.
Speaking following the daylight robbery at gunpoint of Australian Paralympic sailor Liesl Tesch and physiotherapist Sarah Ross in Rio, Chiller also said the planned 100,000-strong security force for the Games "doesn't seem ... enough"
"We will look closer to the time, day to day and on an hour by hour basis, whether there will be no go zones ... and maybe curfews," Chiller told reporters in Sydney.
Tesch and Sarah Ross were robbed on Sunday (Monday AEST), saying they were threatened with guns, pushed to the ground and had their bikes stolen while in Rio for training.
"It's not an isolated incident," Chiller said.
"There have been several incidents over the last couple of months involving our team members and other Australians in Rio.
"We are demanding that steps and measures are taken to ensure that all our team members who go to Rio for the Olympic Games next month will be safe."
The AOC had written to Games organisers pleading for extra security precautions as soon as possible "before an athlete gets hurt".
The Rio Organising Committee has promised to mobilise a 100,000-strong force of police, military and other personnel in time for the Olympic Games which begin on August 5.
The security force will remain in place for the Paralympics which begin September 7.
Chiller said the AOC had placed a private security firm in Rio on standby for the Games.
"We will now be having full face-to-face briefings with every single team member when they arrive in Rio about safety and security," she said.
"It's our duty of care to athletes, officials and family and friends to do everything within our power that it is a safe and secure environment for everyone.
"Being in the village and being in a training venue is the safest place to be. The protocols for our athletes after those hours will be especially rigorous."
Tesch warned her fellow athletes to be careful in Rio.
"It's a pretty scary place to be," she told ABC News 24.
"This is not a statistic in this city, it's a reality ... you can't be too careful here."