Victoria has gone a second straight day without a new locally acquired COVID-19 case, although a technical issue has left thousands awaiting test results.
There were no local cases reported in Victoria on Friday, with the sole new infection recorded in hotel quarantine.
It pushes the number of active cases in the state up to 39.
However, some 10,000 test results were delayed on Thursday as one of Victoria's private pathology labs experienced a technical outage that delayed negative test results.
"The outage does not affect the total positive cases reported," the health department tweeted on Friday.
"The outage is being restored and these results are expected to be reported in tomorrow's update."
It means only 23,108 tests were processed in the 24 hours to midnight on Thursday, down about a third on 30,000-plus results seen over the past four days.
Victoria's total testing figure over the past week is almost 200,000, as the state tries to stamp out the Black Rock cluster.
Health authorities have confirmed a COVID-positive man, who attended Boxing Day sales and the second day of the Test at the MCG, is linked to Sydney's northern beaches coronavirus outbreak.
But it still unknown how he caught the virus, having not visited NSW or any high-risk exposure sites.
Contact tracers are trying to establish whether there is a link to that mystery case and the 27 others from the outbreak linked to a Thai restaurant in the Melbourne bayside suburb of Black Rock.
"It's from Sydney. Exactly how it got from Sydney to here, that is less clear. But it's exactly the same strain as NSW authorities are battling now," Premier Daniel Andrews said on Thursday.
The Vermont South man in his 30s is feared to have caught the virus either at Chadstone Shopping Centre on Boxing Day or the MCG Test the day after, with the venues deemed possible acquisition sites.
Authorities have contacted 1700 of the 8000 patrons registered in zone five of the Great Southern Stand of the MCG.
They've been asked to get tested and isolate until they return a negative result.
The same advice has been given to shoppers who went to 11 Chadstone stores, including the newly-added retailer Zara, from 6am to 1.30pm on Boxing Day.
The health department listed precise times and locations for each store on Thursday, as Mr Andrews returned from leave ahead of Friday's national cabinet meeting of state and federal leaders.
People in Australia must stay at least 1.5 metres away from others. Check your jurisdiction'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 sbs.com.au/coronavirus.
Please check the relevant guidelines for your state or territory: NSW, Victoria, Queensland, Western Australia, South Australia, Northern Territory, ACT, Tasmania.
