Contact tracers used genomic sequencing to link the source of those infections to someone in NSW’s hotel quarantine program, but how the virus made it into the community remains a mystery.
It is the second coronavirus scare for the state in 24 hours after three cases were confirmed on the same floor of a quarantine hotel in the city’s CBD.
NSW Health authorities are investigating whether it was an instance of Covid-19 spreading among returned travellers in hotel quarantine.
All three cases arrived in Sydney on the same flight from Doha on 1 June and stayed in adjacent rooms at the Radisson Blu hotel.
Authorities have since contacted other returned travellers who had been discharged from the fourth floor of the hotel and have asked them to isolate and get tested.