Australia's Olympic team leader is urging Brazilian authorities to implement Olympic-scale security in Rio de Janeiro "before an athlete gets hurt".

Two members of the Australian Paralympic sailing squad were robbed at gunpoint in Rio during the weekend, highlighting fears of crime against foreign athletes ahead of the Summer Games in August.

An estimated 85,000 police and soldiers will be patrolling the streets during the Olympics and Paralympics, but violent crime remains a fact of life in Rio.

"Maybe the organizing committee should mobilize its defense force for the games early," Kitty Chiller, Australia's Olympic team leader, said on Tuesday. "Do it now."

Chiller said she has written to the head of the Rio organizing committee and to the city's mayor, Eduardo Paes, to express concerns.

"We're demanding that the level of the security forces be reviewed, and also that they be mobilized earlier," she said.

The weekend incident "was extremely concerning and disturbing", she added. "It's not an isolated incident. Athletes have been mugged while training or competing in Rio test events, and we want them protected.

"We have briefed our athletes leading into the Games. Basically, we are saying that if you are confronted by criminals, comply, hand over your belongings and don't argue."

A statement from Australian Sailing said Paralympic sailor Liesl Tesch and team official Sarah Ross were confronted by two men while riding their bicycles in a Rio park on Sunday. One of the men was carrying a pistol, and the women were robbed of their bikes.

Tesch raced at the Paralympic sailing venue on Monday, and was quotedas saying of the robbery, "We are both shaken, but physically we're both OK."