Two Australian Olympic rowing coaches have been robbed at knifepoint while walking to their hotel in Rio de Janeiro.

The pair were confronted by two men on Friday night (Rio time) and threatened with a knife before being attacked.

"They were yelling, intimidating with the use of their voice and of course the knife, about an eight-inch knife, was enough to scare the pants off anyone really," Greg Nance, the deputy director of welfare for the Australian Olympic team, said.

They were forced to hand over a small amount of cash, mobile phones and Olympic merchandise.

Nance said the knife "was used in a very threatening manner" and the coaches were "shaken".

"I do believe though the circumstances look like a very opportunistic crime," Nance said.

"For a brief few minutes our guys were the only people in the street, and it's very dark and they got caught out by these two fellows lurking there."

It is not the first brush with crime in Rio for the Australian team.

Before the Games started, Paralympian Liesl Tesch was robbed at gunpoint and Australia's team reported a theft in the Olympic Village after their building was evacuated due to a fire alarm.