Victoria on Saturday reported three deaths, plus 397 new cases, significantly less than Thursday's peak of 723.
Thirty-seven of the new cases are linked to current outbreaks, with another 360 under investigation.
It is understood the three deaths - a man in his 80s, a woman in her 80s and a woman in her 90s - are all connected to the .
Saturday's numbers come after two straight days where the reported case numbers rose above 600.
"While there is always a temptation to try and read trends into these numbers, there is a growing concern in relation to the number of community transmission cases," Premier Daniel Andrews told reporters.
Mr Andrews revealed the state was investigating at least 49 "mystery cases", where contact tracers have been unable to find the original source of infection.
“Forty-nine doesn't seem a very large number but ... that can mean there are many more than 49 [people] out there ... infecting other people unbeknownst to them,” he said.
“You cannot be certain if there is even more further community transmission, more mystery cases out there. That is, in some respects, our biggest challenge.”
The Cedar Meats abattoir, the site of one of Victoria’s biggest clusters, has also reported a new positive case among staff. All staff have been asked to self-isolate, with close contacts tested on-site.
There are now 5,919 active cases in the state, and the death toll sits at 116. The national death toll has reached 201.
There are 379 people with COVID-19 in hospital in Victoria, 41 of whom are in intensive care.
The state's chief health officer, Brett Sutton, said a New Zealand-style lockdown was being explored - restrictions which saw all businesses closed except for essential services.
Experts are working over the weekend to analyse infection data from the first half of Victoria's six-week lockdown, but Mr Andrews admitted further restrictions could prove a "circuit breaker" for rising COVID-19 cases.
Decisions would be based on state and national modelling, which Mr Andrews wanted publicly released.
"What we have at the moment are numbers that are too high of community transmission and that is a concern to us," he told reporters.
"It is not a tap you can just turn on or off.
"They (further restrictions) are not decisions that would be taken lightly because there are significant costs ... even minor changes have a significant cost."
Eight coronavirus fatalities were reported on Friday, along with 627 cases. Mr Andrews also revealed around on Thursday by the Australian Defence Force were not at home.
A 3.5 hour drive ‘for a Big Mac’
The state government urged all Victorians to abide by the rules after revealing infringements were handed down to residents brazenly flouting health orders on Friday.
Police Minister Lisa Neville said Victoria Police was still seeing “appalling” instances of people travelling out of their postcodes and breaching lockdown restrictions.
“I am fed up with it. Victoria Police are fed up with it,” she told reporters.
Ms Neville said police fined someone on Friday for driving from Melbourne to Wodonga, which takes around three and a half hours, “to have a Big Mac”.
Another person was fined for driving an hour and a half from Melbourne to Ballarat “for fresh air”, while another took an hour-long drive from Werribee to Springvale “to buy groceries”, she said.
“Just in case there is any doubt at all, there is absolutely no reason or need for [that].”
Ms Neville thanked Victorians who were following the rules, but was visibly exasperated by those who were caught breaching them.
Victoria Police Minister Lisa Neville speaks to the media Source: AAP
“Why would people think that is OK? It can't be because people aren't aware of the rules,” she said.
“I think there is no question when Victoria Police pull people over they are aware of the rules, but these people have made a decision to breach, blatantly breach, the chief health officer's directives.”
Residents in metropolitan Melbourne are subject to stay-at-home orders and can only leave home for essential work, study, exercise or care responsibilities. It is also mandatory to wear masks in public.
People in Australia must stay at least 1.5 metres away from others. Check your state’s restrictions on gathering limits.
If you are experiencing cold or flu symptoms, stay home and arrange a test by calling your doctor or contact the Coronavirus Health Information Hotline on 1800 020 080. News and information is available in 63 languages at
