There are 80 new Covid-19 community cases, with 77 in Auckland, two in Waikato and one in Northland.
As of 10am, 34 of these cases are linked and 46 remain unlinked, the Ministry of Health reported in a press release on Sunday.
This brings the total number of cases in the current Delta outbreak to 2572.
Interviews are continuing with the Blenheim case, which is now understood to be unvaccinated, a ministry spokesperson said.
Two of the person’s household contacts have returned negative test results and are also in isolation.
On Saturday, the South Island reported its first community case of Covid-19 since 2020.
A Ministry of Health spokesperson said the Blenheim case flew from Rotorua to Blenheim on October 21, and had sought a test upon arrival due to a sore throat.
Consequently, Flight NZ8231 Rotorua to Wellington at 7am, and Flight NZ8725 Wellington to Blenheim at 9am, and Wellington Airport on Thursday, October 21, from 8.15am to 9am, were listed as locations of interest.
The ministry said initial interviews suggested the person is likely linked to the Te Awamutu cluster.
The Blenheim case prompted experts to call for tougher measures to limit the transmission of Covid-19 between the North and South islands.
Meanwhile, the four cases in Northland belong to one family, with two of the infected members under the age of 12.
The Northland cases came after two people allowed to travel from Auckland to Kaikohe tested positive for Covid-19.
On Saturday, more Northland and Blenheim locations were added to the locations of interest list.
On Friday, Prime Minister Jacinda Ardern announced a new traffic light system which would give more freedoms to fully-vaccinated Kiwis.
The system would see the end of lockdowns for DHBs with 90 per cent of its eligible population fully vaccinated.