There are two new coronavirus cases in New Zealand on Sunday, the Ministry of Health says, one of whom is a health worker in Auckland's quarantine facility.
It's the first time in a month there have been no new cases linked to the Auckland cluster.
The other case reported on Sunday is an overseas returnee in managed isolation.
In a statement, the Ministry said five household contacts of the health worker are isolating at home and being tested on Sunday.
The Ministry said the Auckland Regional Public Health Service has worked closely with the quarantine facility - the city's Jet Park Hotel - to double-check protocols and procedures.
"This case is still being investigated to determine if the infection came from the community or from within the quarantine facility, though at this stage no obvious links to other cases in the community have been established," the Ministry said.
"Thorough tracing of which people in quarantine the health worker had contact with is being undertaken, as is genome testing to see what strain of the virus the health worker has to help identify the source."
The quarantine health worker testing positive reinforces the importance of protections already in place, the Ministry says.
"This is the first time a staff member at Jet Park has tested positive for COVID-19 in five-and-a-half months of operation," a Ministry spokesman says.
"We know that staff working in the quarantine facility are at a higher risk of infection than the general population.
"Staff at the facility regarded as close contacts have been stood down and a deep clean of staff areas at the facility has been completed."
All quarantine facility staff will be tested in the next 48 hours, the spokesman says.
"This case, which was found from routine weekly testing, demonstrates the value of the regular testing of all staff.
"The health worker was tested last week and returned a negative test, so has picked up the virus in between the weekly tests which are done as part of the regular testing of people working in the quarantine facility."
Genomic testing results are expected to be released on Monday as part of the investigation into the case.
Auckland cluster latest
Sixty-three people linked to Auckland's community cluster remain in quarantine at the Jet Park Hotel. This includes 38 people who have tested positive for COVID-19 along with their household contacts.
Since August 11, contact tracers have identified 3664 close contacts of cases - 3650 of whom have been contacted and told to self-isolate.
There are three people in hospital with COVID-19 infection. One is isolating on a ward in Auckland City Hospital, while the other two - one at North Shore, one at Waikato - are in intensive care.
The total number of confirmed COVID-19 cases in New Zealand is 1446.
Labratories on Saturday processed 7211 tests, bringing the total to 864,469.