The refugees came from the Australian offshore detention camps in Manus (Papua New Guinea) and Nauru, and were brought to the mainland for medical treatment.
They are being held at the Park Hotel in Carlton, where 22 of them now have Covid-19, with one hospitalised.
The Refugee Action Coalition's Ian Rintoul claimed the proper protocols of separating the infected from those without the virus had been ignored by Australian officials.
He said the Australian government has created a Covid incubator in the Park Hotel.