'Positive news' on local COVID-19 cases, but NSW Premier expects number to rise

"The Victorian government has imposed certain restrictions on their own citizens in regional Victoria and it would be a bit inconsistent if we went further than what their own government did in terms of what they're allowed to do," the Premier told ABC News Breakfast on Thursday morning.

Ms Berejiklian claimed NSW health officials did not have clarity around how many cases were occurring in regional Victoria.

Victoria has recorded 11 new cases in the latest 24-hour reporting period, including four new cases in regional Victoria which all had known sources.

The locally acquired cases in NSW - two in Sydney's south west, and one in western Sydney - remain under investigation. As of Wednesday night they had not been linked to each other, and there were no links between the new cases and existing clusters.

But Ms Berejiklian says NSW Health has made some progress regarding the three mystery cases which threaten to reset Queensland's border clock.

"But I also do anticipate the number of community cases will go up today simply because, when you identify new individuals with the virus, often their families or the people living in their household hadn't had enough time or notice to take action and often you will find they will get it as well," she said on Today.

During her ABC News Breakfast appearance, Ms Berejiklian said she did not want to put unnecessary pressure on her state's contact tracers to meet the 48-hour deadline to link cases to known clusters set by the Queensland government.

"Sometimes it might take them a couple of hours, sometimes it might take them a few days. I don't want to put additional pressure on unnecessarily. They should be able to do their jobs," she said.

NSW Deputy Chief Medical Officer Jeremy McAnulty says authorities are still hopeful they will be able to track down the source of three mystery coronavirus cases.

Asked on the Today show if he thought it was possible NSW would record the 28 days without community transmission needed for Queensland to reopen its border, Dr McAnulty was not optimistic.

"Look, it is hard," he admitted. "We've seen around the world where countries or jurisdictions think they are free of the virus and then because it's a stealth virus ... it can go undetected under the surface.

"You can't be confident that it's not there, and so our assumption is always that it may be there. Therefore, don't relax, don't be complacent, come forward and get tested."

On Wednesday evening, NSW Health called on people who went to Ripples restaurant in Milson’s Point on Saturday October 3 from 8pm to 10.30pm to self isolate for 14 days and get tested. A COVID-19 case attended that restaurant, but the details of several walk-in diners were not recorded.

People who had attended a pilates class at Fitness First Carlingford on Saturday October 3 between 8.15am and 9.15am were also directed to get tested immediately and self isolate for 14 days regardless of test results.

People who went to other venues around Sydney were considered casual contacts, and have been asked to monitor for symptoms. A full list of those venues is on the NSW Health website.