West Australians separated from loved ones in NSW face an anxious wait to learn whether they can still reunite for Christmas.
Premier Mark McGowan has yet to decide whether his state will reopen its borders to NSW as scheduled, saying he will await further health advice over the weekend related to a Sydney quarantine hotel cleaner's infection.
It comes despite genome sequencing revealing the woman contracted the virus at work, rather than in the community.
WA remains on track to open up to Victoria from Tuesday, dropping the 14-day requirement for travel from that state.
But a decision on whether the NSW border will reopen from the same date won't be made until Monday when further test results are available.
Mr McGowan said he would be guided by advice from WA's chief health officer Andy Robertson in making his decision on NSW.
"As we saw in Victoria, the virus can bubble away in communities without it being picked up," he said.
"People can be asymptomatic. People can not go to see the doctor.
"In coming days, I'm sure NSW will do many thousands of tests. That will provide us with the evidence we need to make a final decision on Monday."
Federal cabinet minister Peter Dutton said WA should have faith in the ability of NSW to nail down the source of the infection.
But another Morrison government minister, WA's Christian Porter, backed the premier's call.
"It would be a bad thing for the state if you didn't have travel because of one case of community transmission in NSW, but I think Premier McGowan did the right thing not to make the decision instantly and to just give it a bit of thought over a few days," he said.
Travellers from NSW and Victoria have been blocked from entering WA for almost nine months unless they went into quarantine and, until recently, secured exemptions.
Australian Associated Press