Queensland's health minister is concerned about undetected coronavirus cases in the state after two people tested positive for COVID-19.
Health Minister Yvette D'Ath says a man in his 40s who visited Sydney's northern beaches and a female superyacht crew member in her 20s in Cairns have COVID-19.
Ms D'Ath says Queensland has now 100 days without community spread, and the 23,609 tests conducted in the last 48 hours had found only two COVID-19 cases.
But those two cases and sewage tests at Wynnum, Bargara and Bundaberg show there are more positive cases in the state.
"We cannot afford to get complacent because with the positive sewage (test) that we have, and the fact that we have this positive case from the northern beaches," Ms D'Ath told reporters on Thursday.
"We believe that we have positive cases in Queensland.
"We hope every one of those positive cases are in quarantine and isolating as directed."
Ms D'Ath said the male traveller tested negative after getting back from Sydney on Friday, but he later became unwell and tested positive on Wednesday night.
The man has self-isolated at his home in the southeast since he returned and has had no contact with the community.
"This is the gold standard of what we expect of anyone who has travelled from the northern beaches and has been told to go into quarantine in Queensland, so we thank that person for that," Ms D'Ath said.
In contrast, police are investigating those aboard a superyacht in Cairns after a crew member tested positive.
The vessel arrived in Queensland on Monday, and a female crew member in her 20s who tested positive was taken to hospital.
Ms D'Ath said the 14 guests and six crew members have not been sharing information about their movements for contact-tracing.
"We are very disappointed that this superyacht is not cooperating, and providing factual correct information to the Queensland Police Service," she said.
Chief Health Officer Jeannette Young also cast doubt on the NSW road border reopening on January 8.
She indicated it may not happen until January 13 if NSW Health can't find the infection source for a Sydney van driver diagnosed on December 16.
"If that remains unlinked, it will be 28 days from that date before we could open (the border)," Dr Young said.
Meanwhile, an interstate war of words about the border closure has escalated.
On Wednesday, Premier Annastacia Palaszczuk said it was "a bit rich" for her NSW counterpart Gladys Berejikilian to criticise border closures when the outbreak was in Sydney.
A Queensland government request for the ADF to support police at the border checkpoints was also rejected by the federal government.
Deputy Premier Steven Miles also challenged federal Emergency Management Minister David Littleproud to help pay half the border infrastructure bill for border councils.
In a letter seen by AAP, he wrote that the federal government in February had refused to split the bill under Disaster Recovery Funding Arrangements (DRFA).
Dr Miles said it was not too late for the federal government to split the bill with the state.
"I call on the Commonwealth Government to reconsider its position and make available funding to local governments to assist them in covering costs associated with the pandemic," he wrote.