Victoria is understood to have 429 new cases of coronavirus on Monday.
Numbers and details of any further fatalities are not yet known.
Premier Daniel Andrews will confirm the latest daily tally in an update on Monday afternoon, at which he is also expected to reveal the full details of further tough restrictions for Victoria, including closing some workplaces.
An exact time for that update is not yet available.
Elsewhere, NSW had 13 new cases on Monday – three in returned overseas travellers and one in someone from Victoria. The remainder are community transmission, including one that authorities have been unable to trace back to any known outbreaks.
It is one of seven mystery infections in Sydney’s south-west, west, east and central regions.
“We need to assume every time we go into the community that people in and around us have the virus,” Premier Gladys Berejiklian said on Monday.
“That’s how we need to act and what we need to remember.”
Queensland had no new coronavirus cases to report on Monday.
But Premier Annastacia Palaszczuk has demanded quarantine “loopholes” be closed after one of the state’s positive COVID cases was revealed to be a returning consular official who was exempt.
“I don’t think the time is right now for those exemptions,” she said, adding she would raise the issue at national cabinet.
Also on Monday, Mr Andrews is expected to give more details of strict stage four measures for businesses and workplaces, after imposing a curfew and other restrictions across metropolitan Melbourne on Sunday.
Victoria had 671 new COVID cases on Sunday – its second-highest daily total yet in the pandemic.
Seven further deaths were also confirmed, bringing the state’s toll to 123 and the national toll to 208.
Under rules that will remain until at least September 13, Melbourne has a daily 8pm-5am curfew, while regional Victoria has gone to stage three measures.
Melbourne residents can exercise for only an hour a day and can’t travel more than five kilometres from home unless it is to work.
Only one person per household can shop for groceries each day, while recreational sports such as tennis and golf have been banned.
With a state of disaster declared, police have additional powers to fine anyone caught breaking curfew or further than five kilometres from home without reasonable excuse.
Mr Andrews has flagged further announcements on employment rules on Monday, including closing workplaces in certain industries.
“There will be significant changes to a number of workplaces in terms of how much they’re doing,” he said.
But he assured Victorians that supermarkets, grocery stores and bottle-os would remain open in a bid to discourage a fresh wave of panic-buying.
While acknowledging the drastic moves were necessary, the Victorian Chamber of Commerce said they would undoubtedly mean the end for many businesses.
The Victoria Tourism Industry Council said the restrictions would further devastate the state’s ailing tourism and event industry.
Mitchell Shire, to Melbourne’s north, has been reclassified as a regional municipality, meaning it will remain under stage three rules.