Three cases were recorded in hotel quarantine in the 24 hours to 8pm on Saturday.

Some 8811 people were tested in the reporting period, causing health authorities to again urge more people to come forward.

More than 10,500 people were tested the previous day.

Fragments of the virus were found in the sewage network at Warriewood, Liverpool and Malabar overnight.

NSW Health says the detections may reflect known recent confirmed cases in these areas, but people living or working there should be on high alert.

The health department urged people not to drop their guard as gathering restrictions ease.

Greater Sydney and Wollongong residents are now allowed to have 30 visitors in their homes, while 50 people can attend outdoor gatherings including in yards.

Since Friday, 300 guests are allowed at weddings and funerals, while caps have been removed on corporate events, religious gatherings and hospitality venues. However, the "four square metre" rule still applies.

Masks are also no longer compulsory in shops, but people are still obliged to wear them on public transport, at religious gatherings, in gaming rooms, at hairdressers and beauticians and in public-facing hospitality jobs.

Tasmania and South Australia on Sunday relaxed their restrictions on travel from NSW.

All NSW residents will from Monday be able to travel to Queensland.

Elsewhere, border restrictions imposed by the ACT and Victoria on Greater Sydney have relaxed.

Australian Associated Press