Victoria has recorded eight locally-acquired coronavirus cases, with the latest case being a staff member at a private school 50 kilometres west of Melbourne.
In a statement released on Wednesday evening, the Principal of Bacchus Marsh Grammar School confirmed a member of the teaching staff had tested positive.
They had attended a staff day on 12 July but had not been in contact with students on Tuesday or Wednesday.
"As a result of this, all staff who were at the Staff Day on Monday 12 July have been directed by the COVID-19 Public Health Division Department of Health to isolate and be tested," Principal Andrew A. Neal said.
Classes have been cancelled at both of the school's campuses for the rest of the week.
Four of the new cases are residents on the third floor of the Ariele Apartments in Maribyrnong, which has been in lockdown since Monday evening.
Among them is a man in his 60s who subsequently infected his parents, who are aged in their 80s and live in Craigieburn.
COVID-19 Commander Jeroen Weimar urged anyone who has visited an exposure site or has symptoms to get tested.
"The next two days are particularly critical," he told reporters on Wednesday.
"We are right on the heels of this particular outbreak."
The man attended an AFL match between Carlton and Geelong on Saturday and was seated in level two of the MCC section of the Melbourne Cricket Ground. He also visited Highpoint shopping centre.
Some 200 residents of the Ariele Apartments were forced into 14 days of quarantine after a group of removalists from NSW conducted a pick up at the complex on Thursday while infectious.
Mr Weimar confirmed the three removalists, two of whom have tested positive, weren't wearing masks, in a breach of their workers permit conditions.
The trio of removalists, two of whom have tested positive, did a drop off at a Craigieburn home the same day, as well as visited several petrol stations and fast-food restaurants, which have been listed as tier-one exposure sites.
It is believed they slept in their trucks on Thursday night before travelling to SA.
The remaining new case is a man in his 30s who attended Coles Craigieburn on Saturday at the same time as a member of a family who recently returned from Sydney while infected with COVID-19.
Authorities said three members of the family flew into Melbourne on 4 July, while a fourth drove back on Thursday.
The family, who live in the local government area of Hume, tested negative shortly after arrival but two became symptomatic and were swabbed again on Sunday, returning positive results on Monday morning.
A third family member tested positive on Tuesday, while the fourth tested positive on Wednesday.
The new cases will be included in Thursday's daily figures.
War of words over pandemic support
It comes as a war of words has broke out between the state and federal governments over financial support for NSW.
Prime Minister Scott Morrison on Tuesday announced a new federal support package following the COVID-19 outbreak in Sydney that has infected almost 700 people and claimed the lives of two.
The package will be jointly funded by the Commonwealth and NSW and offered to other states and territories if they have to impose extended lockdowns.
It was not received warmly by the Victorian government, which only received federal support during its fourth lockdown after repeated requests.
"Victorians are rightly sick and tired of having to beg for every scrap of support from the federal government," a spokesperson for the premier's office said in a statement on Tuesday.
"It shouldn't take a crisis in Sydney for the Prime Minister to take action but we are seeing the same double standard time and time again. His job is not to be the Prime Minister for NSW."
Treasurer Josh Frydenberg told ABC's 7.30 program people were "sick" of Premier Daniel Andrews' "whinging and his politicking of the crisis".
"Victoria was offered a 50-50 split and decided to reject it. Now we've put in place a system with NSW that can be extended and expanded to other states should they incur a lengthy lockdown," he said.
Treasurer Josh Frydenberg speaks to the media during a press conference at Parliament House. Source: AAP
Industry Support and Recovery Minister Martin Pakula told reporters the federal government's treatment of Victoria and NSW has been "unequal".
"We've spent a year hearing about gold standard and now it's gone from gold standard to gold-plated support," he said.
"What we've seen in regards to NSW is support and comfort ... that's what should've happened here as well, rather than the extreme politicisation, the finger-pointing and the blaming that was going on from the federal government."
As a result of this result all staff who were at the Staff Day on Monday 12 July have been directed by the COVID-19 Public Health Division Department of Health to isolate and be tested.