The Auckland Covid-19 community case announced today is a person who lives next to a managed isolation hotel.
Health officials have now completed a detailed interview with the woman, who is a student in her 20s.
She lives alone in the Vincent Residences, an apartment block in the CBD which is next to the Grand Millennium Hotel.
The hotel, which is a managed isolation facility, had a fire alarm evacuation on Monday night, but that evacuation is not the source of the infection because the woman was already symptomatic earlier that same day.
A Managed Isolation and Quarantine spokesperson earlier said guests were evacuated using strict infection control protocols including PPE, masks and physical distancing.
Anyone who visited the Vincent Residences as a visitor or a resident, since Saturday, is urged to get a Covid test and isolate until the results are returned.
Director of Public Health Dr Caroline McElnay said all common areas in the apartment building will be closed and a mobile testing station for residents would be on site there tonight.
"Health authorities are working closely with the body corporate and a cleaning company is going in today to do a deep clean of the common areas of the apartment building, including stairwells, lifts and the lobby," Dr McElnay said.
She said the woman works at A-Z Collection as a shop assistant in a customer facing role.
"This person became symptomatic on the 9th of November, was tested on the 10th of November, was asked to isolate and then went to work on the 11th of November.
"We now know that this case called in sick to work after receiving the advice to isolate, but after a conversation with their manager went to work and wore a mask."
A-Z Collection was closed today and undergoing a deep clean, she said.
Three close contacts of the woman have been identified. They are being followed up, isolated and tested, Dr McElnay said.
These contacts include a colleague and two friends and they all report being well, however the two friends are being transferred to the Auckland quarantine facility as a precaution, she said. One of the friends lives alone in the Vincent Residences, the same place as the woman, she said.
Te Pūnaha Matatini director Professor Shaun Hendy said the Auckland case was similar to the August cluster where the source was unknown.
"Anyone in Auckland, particularly anyone who has been in the Auckland CBD in the last two weeks, should seek a test if they have any of the symptoms associated with Covid-19. Anyone who has visited A-Z Collections this week should self-isolate and seek a test," Hendy said.
He said contact tracing and/or genomics could help identify a link, but if that could not be established Auckland could be looking at moving up alert levels.
"Our testing rates and use of the app are higher than they were in early August, so I think we are likely in a better position now than we were then."
University of Auckland professor Siouxsie Wiles said the pandemic was "growing exponentially overseas, so we will likely see more and more people arriving in New Zealand incubating the virus".
"Quickly identifying any community cases means we should be able to stop any outbreaks using testing, contact tracing, and isolation rather than having to move up the alert levels."