An expert has warned that Sydney could be plunged into a snap lockdown if health authorities are unable to determine how two people from Bondi contracted Covid-19.
A man in his 60s became the first case of community transmission in 40 days in New South Wales, with his household contact also recording a positive result late on Wednesday.
Contact tracers are now scrambling to find the source of the infection after confirming the man has not been overseas recently, but works as a driver transporting international flight crews.
There were 19 virus exposure sites were identified across six Sydney suburbs and regional NSW on Wednesday.
Epidemiologist Professor Mike Toole said a strict lockdown could be on the cards if the virus isn't contained within the next 24 hours.
Pictured: A nurse collecting Covid-19 test samples at the Bondi drive-through testing clinic
Six suburbs have been listed as having Covid-19 exposure sites, spreading from North Ryde in Sydney's north-west to Redfern in the inner-west and Bondi in the east
'[If] you get a number of cases arising from say, more than one of those exposure sites, and they may not be linked to each other, then I think we would have to consider stricter lockdowns,' he told the ABC's Patricia Karvelas.
Exposure sites include Events Cinema at Bondi Junction for a screening of The Hitman's Wife's Bodyguard, Myer and David Jones in Bondi Junction, Harry's Coffee and Kitchen in Bondi Junction and cafes in Vaucluse and North Ryde.
Locations in the towns of Moree, Forbes, Dubbo, Coonabarabran have also been listed.
Professor Tool said: 'We know once you see this pattern getting a little out of control, you must go in quickly.'
'And that usually leads to a short lockdown rather than the kind of dragged out lockdowns you have seen in places like the UK.'
He said Victoria's recent outbreak was an example of how quickly the other strains of the virus can 'spread very quickly through just casual contact one of those environments'.
A couple donning face masks are pictured walking nearby a David Jones store which was flagged as a Covid exposure spot
Customers wearing face masks at Westfield Bondi Junction. Contact tracers are racing to find hundreds of people who may have been exposed to the virus in the shopping centre
The last Covid-19 cases in NSW were in May when a husband and wife from Sydney's eastern suburbs tested positive.
At the time, Premier Gladys Berejiklian introduced a range of restrictions including mandatory mask wearing indoors and on public transport, no dancing at indoor venues or standing up in bars, and a maximum of 20 people allowed in homes.
The WA and Tasmanian governments have told anyone who has recently returned from NSW to check the list of exposure sites, and get tested and isolate if they have been to any of the listed locations.
Investigations are also underway into a potential hotel quarantine breach at Sydney's Radisson Blu hotel.
The National Australia Bank branch in Bondi Junction shopping centre (pictured) has been listed as an exposure site
Bondi JunctionHarry's Coffee and Kitchen (picured) has been listed as an exposure site
All cases are confirmed to be the UK strain, known officially as the Alpha variant, which is highly infectious.
The list of potential exposure sites included a number of stores at Westfield Bondi Junction, which the infected man visited on multiple occasions.
Contact tracers are racing to find Sydneysiders who visited various exposure sites including a David Jones store, a cinema, several cafes and restaurants and a bakery in the city's east and north-west between June 11 and June 15.
The airport worker first attended the Belle Cafe in Vaucluse on June 11 between 9.15am-9.50am and returned on June 12, June 13 and June 14 at various times.
He also attended Sourdough Bakery at Westfield Bondi Junction between 12.40pm-1.10pm on June 11.
He returned to the shopping centre the following day where he shopped in David Jones between 11am-11.40am and Myer between 11.40am-12.15pm.
Another three positive cases at the Radisson (pictured) arrived into Sydney on the same flight from Doha in Qatar on June 1
Authorities are scrambling to track down hundreds of shoppers he may have exposed the virus to at another popular Westfield shopping centre. Pictured: Westfield Bondi Junction
The infected man attended a movie screening of The Hitman's Wife's Bodyguard at Event Cinemas Bondi Junction on Sunday afternoon, June 13 for the 1.45pm screening.
Anyone who attended the 1.45pm screening in cinema 1 at the venue on June 13 is ordered to get tested immediately and self-isolate for 14 days, regardless of the result.
Other movie goers who were at the cinema on Sunday between 1.30pm-4pm are ordered to get tested and self isolate until further notice from authorities.
He also dined at two Vaucluse restaurants including Washoku on June 12 between 12pm-1.30pm and Rocco's on June 14 between 10.55am-11.30am.
The most recent venue he visited was the Celeste Catering Macquarie Park Cemetery Cafe in North Ryde on June 15 between 1pm-1.20pm.
Contact tracers are in the process of identifying and calling close contacts and ordering them to get tested and isolate.
East Village shopping centre in Zetland, inner-Sydney, has been listed as a Covid exposure site - including its Coles supermarket - after an infected person visited on Monday
'Urgent investigations into the source of the infection and contact tracing are underway, as is genome sequencing,' a NSW Health Statement read.
Other venues thought to have been visited by the second positive case include the Coles East Village Shopping Centre in Zetland on Monday June 14 from 11.00am-1pm.
The infected person also went to Taste Growers between the same times on the same date and then visited Wax Car Wash Cafe in Redfern on Monday June 14 from 12pm-3pm.
Bondi Junction's Harry's Coffee and Kitchen and the National Australia Bank branch in Westfield were also added to the list late on Wednesday, along with the Field to Fork eatery in Vaucluse.
The news of a new locally-acquired case sparked long queues at the Bondi drive-through testing clinic (pictured on Wednesday night)
Sydney's 200 Bus from Bondi Junction to North Sydney was another hot spot flagged by NSW Health.
With long lines already forming at drive-thru clinics in the city's east, testing centres extended hours until 10pm for the next three nights to meet public demand.
Meanwhile, NSW Health says it administered a record 17,223 Covid-19 vaccines in the 24 hours to 8pm on Tuesday, including 6,048 at the vaccination centre at Sydney Olympic Park.
The total number of vaccines administered in NSW is now 1,737,557.
SYDNEY VENUES EXPOSED TO COVID-19
- Anyone who attended the following venue at the time listed must get tested and self-isolate for 14 days from the date they were at the venue, regardless of the result.
Bondi Junction, Events Cinema, Sunday, June 13 - 1.30pm-4.00pm
Bondi Junction to North Sydney 200 Bus, From Bondi Junction interchange to Blue St, North Sydney (near North Sydney Station) Tuesday 15 June. Departed approx. 4.25pm, arrived approx. 5pm
- Anyone who attended the following venues at the listed times must call NSW Health on 1800 943 553, get tested and self-isolate until you receive further advice.
Vaucluse, Belle Cafe, Friday, June 11 - 9.15am-9.50am,
Saturday, June 12 - 11.20pm-1.50pm,
Sunday, June 13 - 11.30am-12.00pm,
Tuesday, June 15 - 9.50am-10.25am
Bondi Junction, Sourdough Cafe, Friday, June 11 - 12.40pm-1.10pm
Vaucluse, Belle Cafe, Saturday, June 12 - 10.20am-10.45am
Bondi Junction, David Jones, Saturday, June 12 - 11.00am-11.40am
Bondi Junction, Myer, Saturday, June 12 - 11.10-12.15pm
Events Cinema Bondi Junction: (all screenings other than the Hitman's Wife's Bodyguard), Sunday June 13, 1.30pm-4pm.
Vaucluse, Washoku Vaucluse, Saturday, June 12 - 12.00pm-1.30pm
Vaucluse, Rocco's, Monday, June 14 - 10.55am-11.30am
North Ryde, Celeste Catering Macquarie Park Cemetery Cafe, Tuesday, June 15 - 1.00pm-1.20pm
Zetland, Coles East Village Shopping Centre, Monday, June 14 - 11.00am-1pm.
Zetland, Taste Growers East Village Shopping Centre, Monday, June 14 - 11.00am to 1pm.
Redfern, Wax Car Wash Cafe, Monday, June 14 - 12pm-3pm
Bondi Junction Harry's Coffee and Kitchen, Tuesday, June 15 - 3pm-3.40pm
Bondi Junction NAB in Westfield, Tuesday, June 15 - 2.45pm-3.10pm
Bondi Junction David Jones in Westfield, Tuesday June 15 - 3.30pm-4.15pm
Vaucluse Field to Fork, Friday, June 11 - 12pm-4pm
- Anyone who attended the following venue is a casual contact and must immediately get tested and self-isolate until a negative result is received.
Bondi Fruitologist, Tuesday June 15 - 1pm-2pm