Victoria may have no fresh virus infections for the first time in more than four months amid doubts about the lone case reported by health authorities on Tuesday.

Premier Daniel Andrews said the single mystery case was in someone who had previously tested positive for the virus and further testing was being done to see if it was still an active infection.

If confirmed as an old case, that would make Tuesday Victoria’s first day without new COVID infections since June 9.

Earlier on Tuesday, reporting of the state’s daily tally of cases was delayed as health authorities debated another confirmed case in a Victorian resident who is quarantining interstate after returning from overseas. Under Australian guidelines, however, COVID cases are assigned to the state where they are detected.

“They are, therefore, not a notifiable case in Victoria and that explains, I think, the earlier [release] this morning of two is really one, and the one may not necessarily be an infectious person or an active case,” Mr Andrews said.

“That case today, the one that may well be an instance of shedding the virus, a perfectly natural process, well after your original positive test, is in Melbourne.”

Melbourne’s recent run of low virus numbers offers hope for relaxed restrictions.

Even with one new confirmed infection, Melbourne’s 14-day average of new cases has fallen to down to 6.4. In regional Victoria, where there remain must three active cases, it is 0.4.

The number of mystery cases in the city in the past fortnight has also dropped. It is down to 13, and there are none in the rest of the state.

There was more good news for Australia’s fight against the coronavirus from NSW, where there were only two new locally acquired cases.

There were three more cases in returned travellers.

The two new local infections came after NSW had its first day on Monday since October 6 without community transmission of the virus.

Of Tuesday’s community cases, one is linked to the Liverpool private health clinic cluster and the other is a close contact of a confirmed case linked to someone who attended the childcare centre at Oran Park.

NSW Health remains concerned about testing levels in the state. Testing levels in the Oran Park area have soared in the past week, but remain low across the rest of Sydney.

Tuesday’s results came from 7401 tests across NSW.

By contrast, Victoria’s results came from 11,936 tests. Mr Andrews again urged Victorians to keep getting tested, ahead of virus restrictions potentially being wound back further as soon as next weekend.

“I’ll stand here on Sunday and hopefully be able to confirm for Victorians that, when it comes to retail, pubs, restaurants, cafes, bars, as well as a number of other settings, that we can have what’s been termed a dark opening for, say, the first one or two days of next week and then we can be up and running from then,” he said.

However, he again dashed any hopes that footy mad Victorians might be able to celebrate this weekend’s AFL grand final in groups.

“Ultimately, no one game of footy, no one barbecue or dinner with friends is worth all that can be on offer in a COVID-safe summer and a COVID-safe and COVID-normal 2021,” he said.

“I know what the footy means, whether your team is in the grand final or not. I know what that means. But it’s important we see this thing off properly. Sunday can be a day where we’ll have more to say.”

No new deaths were reported on Tuesday, so Victoria’s COVID toll remains at 817. Australia’s toll is 905.