Fears are growing over a potential third lockdown in Melbourne as a cluster of cases linked to Victoria’s hotel quarantine system grows to 13.

It is understood the state government advisers met overnight to draw up a framework for another lockdown, which could be introduced as early as Friday night, or possibly within days.

Health officials are not just concerned about the growing Holiday Inn cluster, but they are also fearful about virus fragments detected in wastewater across Melbourne.

A source close to Emergency Management Victoria told the Herald Sun authorities feared they had lost control of the outbreak – describing scenes of “pandemonium” at the agency.

They revealed to the newspaper there were major concerns at the failure of contact tracers to match information they had been given by confirmed cases and their close contacts due to the results from the sewage testing.

Authorities believe all the cases linked to the Holiday Inn outbreak are UK strain cases – meaning it could spread more rapidly than the strain that caused chaos in Victoria last year.

In response, the  Herald Sun  reports Victorian health authorities are weighing up a snap lockdown, much like the five-day shutdown in Perth at the beginning of the month.

In WA, residents were only allowed to leave home for an hour to exercise with a mask within 5km, or if they were an essential worker, needed groceries or medical supplies, were receiving health care or were supporting someone with needs.

Schools, gyms and cinemas were also shut, while restaurants and cafes could only serve takeaway.

Under those rules, crowds would also be banned from the Australian Open.