Four members of the Australian women's water polo team have been placed into quarantine in Rio after being struck down with a virus just days out from the opening ceremony.

The four Aussie Stingers athletes are suffering from a gastro-intestinal illness and were separated from their teammates as soon as the squad landed in Rio on Monday, Australian Olympic boss Kitty Chiller said.

The Stingers had been training in Italy in recent weeks before flying to Brazil, ahead of their first game against Russia on Tuesday, local time.

Chiller said the sick team members - who have not been named - would be isolated in an area of the athletes' village that normally houses Australian team officials.