Queensland has recorded no new cases of COVID-19 after genomic sequencing revealed a breach of the Delta variant in hotel quarantine.
No new cases emerged after authorities conducted 13,081 virus tests overnight, authorities said on Tuesday.
A Gold Coast man in his 40s, who tested positive on the weekend, caught the virus while quarantining at the Amora Hotel in Brisbane.
Chief Health Officer Jeannette Young says the man's virus sample has been genomically-sequenced and it matches that of another returned traveller who stayed in the room opposite him at the hotel.
"He has exactly the same sequence, it's identical with no snips different," she told reporters.
Health Minister Yvette D'Ath said five people on the same flight as the initial traveller also caught the same Delta variant.
"It shows how infectious the new Delta strain is, which we are now seeing as the dominant strain across the globe," she said.
"And of course we will look at the CCTV footage in relation to that hotel, but we are confident, more than likely, this is going to be something that's been transferred through the air in that hotel because of the nature of this virus."
The Gold Coast man left hotel quarantine on July 12. He developed symptoms three days later, but he only got tested on the advice of his GP on July 23.
That result showed low amounts of the virus so he was retested on July 25, which revealed he had COVID-19.
None of the man's family members have tested positive for COVID-19 in recent days.
Dr Young said the man was unlikely to infect anyone else but she still has concerns about another two cases who were infectious in the community in Brisbane.
They are a NSW man who allegedly illegally entered Queensland, despite being a close contact of a known Sydney case, and a flight attendant who caught the virus after she picked him up from Ballina Airport and driving him over the border.
The pair face more than $13,000 in fines after police concluded an investigation into their movements.
Once placed in hotel quarantine, the 26-year-old man is accused of opening the door to his room and verbally abusing staff while not wearing a mask.
Police say he continued breaking the quarantine hotel's rules after being warned "and with full knowledge of his positive COVID-19 Delta strain diagnosis".
Earlier on July 15, police alleged he visited a major shopping centre in northern Brisbane where he used untrue information to check in.
He has been issued with three infringement notices for failing to comply with Queensland's COVID-19 directions, with fines totalling more than $9,600 .
Separately, the 36-year-old woman was fined $4,135 and issued with an infringement notice for failure to comply.
The pair visited a number of venues in Brisbane, which along with the Gold Coast venues visited by the third man, total more than 58 COVID-19 exposure sites across the southeast.
Australian Associated Press