Authorities believe a quarantine hotel worker spread COVID-19 from an infected guest to the flight attendant at the centre of Brisbane's latest outbreak.

TIMELINE LEADING UP TO BRISBANE OUTBREAK:

Saturday, June 5
* Flight attendant arrives in Brisbane on Emirates flight and begins two weeks of hotel quarantine

Saturday, June 19
* Attendant released at 9am after three negative tests
* Hours later she tests positive after further routine test for international air crew

Sunday, June 20
* Authorities list exposure sites visited by flight attendant including Brisbane's Portuguese Family Centre

Monday, June 21
* Queensland records zero cases of community transmission

Tuesday, June 22
* Authorities report one new local case involving a man in his 60s
* He was at the Portuguese Family Centre on Saturday, June 19, when the flight attendant was there
* Authorities say risk is low because he and 35 others who were also there have been isolating since Sunday
* Preliminary investigations suggest a quarantine hotel worker infected the flight attendant
* The worker escorted a infected returned traveller from Mongolia to an ambulance and then went to the flight attendant's room to swab her
* Authorities say "it's possible" the worker went directly from escorting the infected traveller to the attendant's room
* They are reviewing CCTV footage to determine if protocols were breached