A Brisbane man threw a party with 25 guests despite being told to self-isolate and wait for his coronavirus test result, which was positive.
The man in his 20s, who lives at Strathpine, tested positive on Friday night after contracting the UK strain of COVID-19 from his male friend in Stafford.
Queensland Health says the latest case hosted 25 people at a party at his home despite being told to isolate after he was tested.
He also visited at least 15 venues in Strathpine, Lawnton, Eatons Hill and East Brisbane while he was infectious.
As well as nine other sites visited by the Stafford man, there are now 26 potential COVID-19 exposure sites across Brisbane.
Authorities warn even more locations could be added if anyone at the party became infected.
"More locations may be added after it was revealed the Strathpine man hosted a gathering of around 25 people at his home between being instructed to isolate and getting his positive test results," Queensland Health said in a statement on Saturday.
All 25 party guests have been ordered into quarantine and are being tested.
Eighteen of the Stafford man's contacts are also self-isolating and are being tested.
Premier Annastacia Palaszczuk said earlier on Saturday she is "comfortable" with the situation as long as everyone maintains social distancing and is tested.
"We are not seeing large-scale community transmission, this is a close contact," she told reporters.
"We're very comfortable where we are at the moment and if anything changes we will update the public."
The nine exposure sites visited by the Stafford man include Westfield Carindale, Bunnings in Stafford and Gasworks at Newstead.
Contact tracers have homed in on the Carindale Westfield and Mama's Italian restaurant in Redcliffe, where the 26-year-old spent the most time and potentially interacted with the most people.
He visited the shopping centre between 12pm and 2:16pm last Saturday and the restaurant between 12:30pm and 3:10pm on Sunday.
The Strathpine man's visit to the Eatons Hill Hotel between 3:45pm and 5:10pm last Saturday is also a concern.
Anyone who has visited those sites is being urged to get tested and isolate until they receive their results.
Chief Health Officer Jeannette Young said both cases are genomically linked to a Princess Alexandra Hospital doctor who was diagnosed on March 12.
The doctor visited four venues in the city's south while she was infectious, with Dr Young saying it was likely the Stafford man had caught the virus from an intermediary yet to be identified.
She said there was a chance there could be two missing links between the doctor and the 26-year-old.
The cluster has sparked a lockdown of Brisbane City and Moreton Bay council area hospitals, aged care facilities, prisons and disability services providers.
NSW, Victoria, Western Australia and the ACT have declared those two council areas as hotspots and all travellers arriving from there must self-isolate and get tested upon arrival.
Tasmania is only warning Brisbane and Moreton Bay travellers to get tested if they become ill, while South Australia and the Northern Territory have not changed their travel rules.
Queensland reported five new cases in hotel quarantine on Saturday, taking the number of active cases to 71.
Ms Palaszczuk has asked the prime minister to halve the number of overseas travellers coming into the state each week, which is currently about 1300 people.
"We're almost at the capacity of our hospitals that we were at the peak of the pandemic," she said.
"That is not to say our hospitals cannot cope, they will be able to cope."
Australian Associated Press