Victorian health officials are scrambling to investigate two returned international travellers who recorded positive Covid-19 test results after leaving hotel quarantine.
Health Minister Martin Foley said the two people had returned conflicting results, suggesting they had previously been infected before arriving in Australia.
The state government will now convene an expert panel to determine how and when they became infected.
“We are also advised that there are two cases that are under investigation at the moment,” Mr Foley said on Sunday morning.
“These are returned travellers who are no longer in quarantine.
“They produced conflicting results on different testing platforms over the past 24 hours.
“This is highly suggestive of historical infections, and an expert review panel will be convened later (on Sunday), to consider those.
“But our public health teams in both cases have taken serology work with these two members of our community and that reinforces the notion that this points to historical infections before these people arrived back in Australia.”
Victoria recorded no new locally acquired cases of Covid-19 on Sunday.
The state’s health department announced zero new local cases about 8.30am, along with two new infections in hotel quarantine.
The number of active cases in Victoria is 51, the same number as Saturday.
The results came from 19,502 tests, while 12,242 vaccine doses were also administered in the past 24 hours.
In another promising sign, no new public exposure sites have been added in the past three days.
The number of venues has steadily fallen over the past fortnight from almost 400 to 113 on Sunday morning.
Victorians have been urged to check the state government’s website for the full and frequently changing list.
Six Covid-19 positive patients remain in hospital, with one case receiving intensive care.
The state’s coronavirus restrictions could be eased again later this week if case numbers continue to remain low, Acting Premier James Merlino said.
“It means that we’ll be in a position later in the week to announce further easing of restrictions,” he said.
“We want to get back to crowds, theatre goers, at sporting events, all of the activities we love, we want to get back there as quickly as we can.”
The rules were last eased on Thursday night with the border between metropolitan Melbourne and regional Victoria removed, along with the 25km metro travel limit.
Masks are no longer required outdoors but are still recommended when social distancing of 1.5m couldn’t be maintained.
Other restrictions eased include two visitors plus dependants per day being permitted to gather inside private homes in Melbourne and up to five people plus dependants in regional Victoria.
Twenty people can gather outside in Melbourne and 50 in regional Victoria.
Gyms can also open across Melbourne with density limits and CovidSafe plans in place, with hair and beauty services now able to operate without masks during service.
The Victorian government says it has also shut down seven businesses over violations of health directions.
During the past three months, health officers have inspected 22,000 business, handing out 17 infringements totalling $52,867 as well a further 913 warnings and notices.
As part of this, a retail store in St Albans was shut down for unauthorised trading during lockdown.
A South Melbourne health and beauty business was also ordered to close for a string of breaches, including exceeding density quotas and having no QR code check-in system.
“This is a warning to all businesses – if you flagrantly breach the rules, we will not hesitate to issue fines or even shut you down to protect public safety,” Acting Police Minister Danny Pearson said.