A petrol station in regional South Australia linked to virus-infected removalists who travelled to SA from Sydney is a potential third COVID-19 exposure site.
Deputy Chief Public Health Officer Emily Kirkpatrick says the site is still being pinpointed, but it's now believed the removalists stopped for rest and fuel after crossing into SA from Victoria early on Friday, July 9.
Dr Kirkpatrick says CCTV footage is being checked and other investigations are underway, and details will be released as soon as the location is confirmed.
"The route coming into South Australia is still being worked through in terms of where those exact stops were," she said.
"It has been a very difficult process piecing together where these particular removalists have been."
However, Dr Kirkpatrck said there had been no confirmed local coronavirus cases linked to the two sites of concern already identified, a service station and a cafe at Tailem Bend, about 100 kilometres east of Adelaide, where the removalists stopped on their return journey.
About 118 people are currently in isolation as close or casual contacts from the two locations after two of three removalists, who relocated a family from Sydney to McLaren Vale, tested positive for coronavirus.
SA Police Commissioner Grant Stevens said there had only been 25 QR code check-ins at the site during the time of concern, compared to 76 credit card transactions.
He said SA Health and police would meet on Thursday to discuss possibly tightening local virus restrictions and the use, or lack thereof, of QR codes would factor into their decision.
"I'm giving people due warning that we are actively considering restrictions for South Australia," Mr Stevens told reporters.
"It is not something we want to do but given what we are facing in Victoria and NSW, we are making decisions that will be in the best interests of South Australia."
So far, all those people considered close contacts of the two NSW men have returned negative tests.
The family of four who relocated to SA have also twice tested negative and are not showing any symptoms despite having contact with the removalists over a five-hour period earlier this month.
Premier Steven Marshall said while all the negative tests were good news, there was still a way to go.
"It's a sigh of relief, but obviously we know the incubation period for this disease can be 14 days and in fact in some cases, it can be even longer," he said.
"So we're not out of the woods."
In response to the NSW outbreak leaking into Victoria, SA is imposing new restrictions on arrivals from Victoria from midnight on Wednesday including mandatory testing within 24 hours of entry.
All freight drivers crossing into the state must also show proof of a negative test undertaken less than 48 hours earlier or alternatively get tested within 24 hours of arrival.
In addition, the state has also tightened the rules for people returning from Sydney, requiring everyone to apply for a special exemption.
About 950 returned last week, but authorities hope the new rules will significantly reduce that number.
Meanwhile, Dr Kirkpatrick has also given details of a possible case of COVID-19 transmission at a quarantine hotel in Adelaide.
She said a man in his 40s had tested positive for the virus after being located close to another positive case.
That earlier case was thought to have been an old infection, but was now being reviewed.
As a result of the latest positive test, about five people in the hotel have had their quarantine periods extended while a number of people recently released were being contacted and would be tested again.