Sydney must keep its growing coronavirus outbreak to less than 100 new cases a day to have any hope of containing it, experts warn.
The first three days of an outbreak is vital to stopping the spread because once cases reach that threshold it is almost impossible to trace.
The outbreak now sits at 28 cases over two days with tends of thousands of tests conducted, but that number could grow immensely over the weekend.
Although New South Wales health authorities have moved quickly on the northern peninsula, the state's Covid detectives have not been able to pinpoint patient zero and the initial source of the outbreak.