There are no cases of Covid-19 today - either in the community or in managed isolation, says the Ministry of Health.
Health officials are yet to reveal whether genomic testing has linked the Hamilton Covid-19 case to others from the Pullman Hotel.
The sequencing will be re-run later this week as the viral load in the sample was so low.
The person stayed in the managed isolation hotel between January 16 and 30 but tested positive on Saturday after isolating at home.
The case is considered to be historic, not infectious and the person has been discharged from the quarantine facility.
"Genomic sequencing is one of a range of factors, alongside clinical history, PCR test results and serology in considering whether cases are historical. The local public health unit has considered these factors in making its clinical assessment of the case."
Health officials have not yet been able to find the source of the infection or link the case to the three other confirmed cases in returnees who stayed at the Pullman then tested positive after leaving.
The total number of active cases in New Zealand is 66 while the total number of confirmed cases is 1964.
On Sunday, 2579 tests were processed and the seven-day rolling average up to yesterday is 3943 tests processed.
And since midday yesterday there were 449,449 Covid Tracer app scans while the seven-day rolling average of scans is 908,448.
The final 60 guests at the Pullman Hotel completed their health checks and were released yesterday.
The returnees are required to complete another five days of self-isolation at home and get another test before re-joining the community.