NSW has recorded 29 new cases of COVID-19 in the community.
Twenty nine locally acquired cases of COVID-19 were detected in the 24 hours to 8pm last night, 17 of which we already knew about. Twelve cases were previously unannounced.
Premier Gladys Berejiklian said the "health advice is evolving", which could mean further restrictions in other parts of Sydney.
Q&A EXPLAINER: Sydney's lockdown rules
EXPLAINER: Is my Sydney suburb in lockdown?
A crisis cabinet meeting will be held later today.
Ms Berejiklian said the reason for additional concern today is because the exposure sites in Sydney have increased beyond the four LGAs currently in lockdown.
"I am putting everybody on notice that we may need to extend (lockdown health orders) during the course of the day or tomorrow."
A raft of new exposure sites were declared overnight, including across the Northern Beaches, North Shore and in western Sydney.
READ MORE: One of Australia's most iconic streets split in two by lockdown
More than 55,000 people were tested in the last 24 hours.
More than a million Sydneysiders went into lockdown just before midnight, because of the growing Bondi COVID cluster.
Strict stay at home orders apply in four LGAs for at least a week, including City of Sydney and Woollahra, Waverley and Randwick in the city's east.
NSW Chief Health Officer Dr Kerry Chant said only 12 of the 29 cases were in isolation during their infectious periods, which is a major concern.
Twenty-eight of the 29 cases are linked to known cases, Dr Chant said, with one mystery case.
READ MORE: Can you get a COVID-19 vaccination yet? State by state guide
She flagged a "workplace outbreak" at Great Ocean Foods in Marrickville in the inner-west between Monday and Friday, this week.
Great Ocean Foods is a retail and wholesale food business, with Dr Chant declaring that workers and delivery drivers have tested positive.
She said people had visited the business and not used the QR check in system.
"We are mopping up a train of transmission," Dr Chant said.
"There have been a number of people that have been infectious in the community unknowingly for a period of time and those individuals could have then already got to their infected their families.
"That is the reason for the escalation in concern."
Foreshadowing a potential ramping up and widening of restrictions, Dr Chant said the situation in Sydney overnight highlighted an increasing number of people have been undetected and infectious in the community.
READ MORE: What Greater Sydney and NSW's tough new COVID-19 restrictions mean
The Delta variant was now believed to be spreading outside the four LGAs, currently in lockdown.
Ms Berejiklian confirmed the Crisis Cabinet Committee will meet later today to decide "whether we need to go further at this stage".
"I do want to foreshadow (wider lockdowns) could well be the case, but that will be dependent upon the health advice provided by Dr Chant and the experts in the next little while."
She said people "should prepare for the news" based on the 29 new cases and broader health updates on the Delta variant this morning.
Some delivery drivers and workers from the Great Ocean Food outbreak site had been infectious and moving across Sydney since Monday, Dr Chant said
"For this virus, that is too long a gap," she said.
"We will need to follow up a large number of people that people have touched in terms of the delivery drivers."
NSW Police Deputy Commissioner Gary Worboys said the investigation into the infected limo driver at the centre of the Bondi cluster is continuing.
There could be an update on the case by Monday, he said, which could clarify reports that the driver did not wear a mask or get tested for the coronavirus in line with guidelines.
Mr Worboys warned Sydney residents can expect "a highly visible police presence" across the weekend, enforcing the health orders.
