A group of Melbourne police officers is in self-isolation after arresting a coronavirus-infected teenager allegedly on a wild crime spree through the city's southeast.
Victoria Police confirmed the boy had tested positive for coronavirus prompting an undisclosed number of their officers into quarantine.
He was one of two boys arrested at a Berwick shopping centre after they broke into a home, threatened a family with a knife, stole their car and crashed it into an unmarked police car on Thursday morning.
Meanwhile, about 500 coronavirus-infected people not at home when authorities came knocking have been referred to Victoria Police.
Victoria has had to ramp up its isolation check-ins by police, defence and health personnel on positive cases after people were repeatedly found not obeying isolation orders.
The doorknocking teams of ADF and health department staff have done 5000 visits since the program started on July 22. Thursday was the biggest single-day of checks, with 1150 homes visited.
"A thousand of those 1150 people could be found where they were supposed to," Premier Daniel Andrews told reporters on Friday.
"The 150 who could not, they have been referred to Victoria Police and I can confirm that there are around 500 people who were not where they should be - this is cumulatively - and they've all been sent to Victoria Police."
Mr Andrews said police would now determine if those people were doing the wrong thing.
On Tuesday, the state government announced a new offence with a $4957 fine for those who fail to self-isolate after testing positive to coronavirus or being identified as a close contact.
The fine can be issued to someone found to breach the requirement to be self-isolating for a second or subsequent time. It is the highest on-the-spot infringement Victoria Police can issue.
Police dished out 196 fines in the 24 hours to Friday morning for public health coronavirus order breaches.
Among them was a man claiming he was out feeding his uncle's horses at 3.40am and a man and woman who went to pick up a pizza because the store wouldn't deliver outside curfew hours.
Two homes were also searched by officers who seized mobile phones and a computer over a planned anti-lockdown protest in the CBD on Sunday.
Two 41-year-old men were arrested on Thursday night over the rally. A Mooroolbark man was charged with incitement - encouraging another person to commit a crime - and was bailed to face court in January.
A Chirnside Park man was released but is expected to be charged with the same offence on Friday.
Police have labelled Sunday's planned protest a "blatant breach" of coronavirus restrictions and say they won't hesitate to hand out $1652 fines or arrest attendees.
Officers checked up on more than 17,600 people at vehicle checkpoints in the 24 hours to Friday morning and did spot checks at more than 4400 homes, businesses and public spaces.
They issued 51 fines for people not wearing face coverings when leaving home for approved reasons, and 43 for curfew breaches.