Three family members diagnosed with COVID-19 in hotel quarantine picked up the virus from fellow returned travellers, NSW Health has confirmed.
Health detectives believe the three cases picked up the virus from a family of four who stayed in the adjoining room of the Adina Apartment Hotel at Sydney's Town Hall.
Health was tipped off to the transmission after all seven people had the same sequence of the virus, despite arriving from different countries at different times.
The three cases have now been reclassified as locally acquired instead of overseas acquired, the government said on Sunday.
NSW Health is investigating how the transmission occurred. The first family is believed to have been infectious between 8 and 11 April.
All guests on the 12th floor of the hotel, where the families stayed, have been retested and returned negative results. Staff who worked on the floor are self-isolating and being tested.
All seven people have been transferred to special health accommodation, where they will stay until they're no longer infectious.
It's not the first time COVID-19 has spread in hotel quarantine, with a couple believed to have spread the virus to a cleaner and two other guests at a Brisbane hotel in January without leaving their room.
The following month, several workers at Melbourne Airport's Holiday Inn contracted COVID-19 from returned travellers.
The 24-case outbreak triggered a five-day, circuit-breaker lockdown in Victoria and led to the temporary suspension of international flights.
NSW now has 67 COVID-19 patients, including one in intensive care.
Six cases were recorded in hotel quarantine in the 24 hours to 8pm on Saturday, from 8088 tests.
Some 550 people were vaccinated in that period, bringing the NSW total to 173,852.
With reporting by SBS News.
