There were only eight new community cases of COVID-19 in Sydney reported on Tuesday, despite a mammoth 44,000 people getting tested in the past 24 hours.
Seven of the cases are linked to the Northern Beaches cluster, and the eighth is a quarantine nurse, New South Wales Premier Gladys Berejiklian said.
"The eighth one... it could actually be an overseas-acquired case. It was a transport nurse, someone who worked in transport in patients in quarantine."
NSW chief health officer Kerry Chant says officials are investigating how the nurse was infected.
"This case has transported several patients but we have identified that they also have transferred positive COVID cases. We are obviously doing urgent genome sequencing to confirm that that is the source of their infection and those results will be available later today."
A close contact of the nurse has also tested positive, which will be included in Wednesday's case numbers.
"A close workplace contact of this healthcare worker has come back positive since the 8pm figures and that will be included in the account for tomorrow," Dr Chant said.
Berejiklian and senior ministers are meeting on Tuesday to decide whether restrictions will be reduced or lifted and an announcement will be made on Wednesday.
NSW health officials also released a list of venues visited by positive cases, including multiple gyms, hotels, cafes and a shopping centre.
It comes after 15 new cases were announced on Monday, all of which were linked to the existing cluster.
Thirty new COVID-19 cases were announced on Sunday which raised concerns over a potential trans-Tasman travel bubble. The New Zealand Government has said it would only proceed if Australia goes 28 days without a local case.
The New Zealand Ministry of Health said it was closely monitoring the situation.
