The case is a returned traveller who was staying on the 11th floor of the Sofitel Wentworth where a security guard is believed to have caught the highly contagious UK virus strain last week from a hotel guest.
Genomic sequencing has since linked all three cases which are the more transmissible B1.1.7 variant of the virus.
The new case is in quarantine and has been in isolation during their infectious period.
“Health believes they acquired it after they went into the hotel so we are being upfront about that. They didn’t have the virus when they came to the hotel,” Berejiklian told reporters on Wednesday.
“It is only fair for us to classify this as community transmission although obviously, they’re in quarantine and not in the community.”
NSW Health said every guest on the 11th floor of the hotel had been re-tested and they were now investigating how the virus spread.
It is still not clear how the security guard contracted the virus as there were no obvious breaches of health protocols.
“Whilst every single case is a concern it does not change anything here in Sydney, there are further easing of restrictions taking place and that will continue,” she added.
“Health believes they acquired it after they went into the hotel so we are being very upfront about that … it could be the missing link between the overseas traveller and the guard.”
NSW Health said there is no shared air-conditioning between the rooms, each has its own unit, and they do not connect to the corridor.
Meanwhile, from Wednesday, people across New South Wales will be permitted to stand and drink at a bar, as promised during the state’s last round of restriction-easing in late February.
Under Public Health Orders, all pubs, clubs, small bars, cellar doors, breweries, distilleries, karaoke bars and casinos must complete a COVID-19 Safety Plan.
– with AAP