Health authorities are hoping a man in Bondi is a false positive, and have convened an expert panel to confirm whether he can be struck from the count.
The four remaining unlinked cases are a man who commutes to his Manly workplace, a man who prompted the alerts for the MLC Centre and Chifley Square in the CBD and two patient transport workers.
Days after the cases were first detected the source of their infections are still unknown.
A handful of other mystery cases have been detected in the northern beaches with no obvious link to the Avalon cluster, which grew by six cases to total to 122 cases. The source of the outbreak is still not known.
NSW Chief Health Officer Dr Kerry Chant urged anyone with symptoms or who had visited one of the more than 100 exposed venues to get tested immediately so that her team could track down undetected cases that could be the missing links to the mystery cases.
“We are at a critical stage in our response and unless we have those high testing rates, it does not give us adequate assurance that we are not missing undetected lines of transmission,” Dr Chant said.
“We may never find the exact source [of the Avalon cluster] … but what’s most important is we are not missing unrecognised chains of transmission,” she said.
A firefighter became the latest unlinked case after returning a positive result on Boxing Day, several days after testing negative.
The firefighter lives in Mona Vale and got tested as a precaution. The essential worker returned to his Fire and Rescue station in Crows Nest in northern Sydney – outside the northern beaches zones – after receiving his initial negative result.
He had also visited the Belrose Hotel on the northern beaches on December 11, prior to his tests. The hotel now has links to three COVID-19 cases. The other two are a hotel staff member in his 20s and a man who stopped into the bottle shop December 17.
The bar worker is considered one of the earliest cases genomically linked to the Avalon cluster, after he recalled having a short-lived fever on December 10. Health authorities don’t yet know how he caught the virus.
The young man was not working the night the firefighter visited the hotel nor the night the man came into the bottle shop, and his co-workers have so far tested negative, leading contact tracers to surmise he did not infect either.
“What we’re looking for is the missing link,” Dr Chant said. “Who else was present at the Belrose?”
She urged anyone who has been to the pub at any time in December and had symptoms of any kind to get tested immediately.
An additional case has been linked to the Rose of Australia Hotel in Erskineville, as well as a household contact of that case.
Their positive test results came in after 8pm last night – 12 days after the initial case at the Rose was detected, demonstrating just how crucial it was for all close contacts and anyone who attended exposed venues to self-isolate for the full 14-day incubation period, Dr Chant said.
She asked anyone nearing the end of their 14-day isolation to get re-tested as an extra precaution.
Premier Gladys Berejiklian said she would make an announcement about any changes to restrictions for New Year’s Eve on Monday or Tuesday.
“The more testing we have overnight, the more we can make those decisions,” Ms Berejiklian said.
“If you have the mildest symptoms please get tested. Those tests will give us confidence to make decisions about New Year’s Eve, especially to the southern parts of northern beaches,” she said.
On Sunday, residents of the lower northern beaches flocked to beach, with socially distanced groups dotting the sand at Manly, Clontarf, Dee Why and Freshwater.
NSW Health released a statement on Sunday advising there were no health orders anywhere in NSW that stopped beaches from being open for swimming, exercise or recreation, so long as the remainder of Greater Sydney residents did not enter the lockdown area.
In the northern part of the northern beaches, only five people could gather for exercise or recreation at the beach and in the southern zone, only 10 people could gather.
NSW Health reminded people who lived outside the northern beaches to stay out unless they had a reasonable excuse to enter.
“A reasonable excuse does not include exercise or recreation,” the NSW Health statement said.
with Harriet Alexander
Kate Aubusson is Health Editor of The Sydney Morning Herald.