Health authorities have confirmed the child who tested positive for Covid-19 this week is connected to the Botany sub-cluster in Auckland.
The girl, aged under 10, is a pupil at Chapel Downs Primary School in Flat Bush.
The school has been closed until at least Monday as the Auckland Regional Public Health Service works to identify close contacts of the pupil, who had been at the school on Monday morning for half an hour.
A letter from the ARPHS sent to the Chapel Downs community yesterday revealed the girl and three other close contacts were dropped off at the school, on Dawson Rd, either just before or about 8.30am.
For some reason, however, they were all picked up again about 9am.
The pupil, who had been tested for Covid-19, later received a positive result that same day.
On Monday, the Ministry of Health confirmed there was one community case to report - a young girl who was epidemiologically linked to an existing case associated with the Botany sub-cluster.
That sub-cluster, now made up of six people, is genomically linked to the wider Auckland August cluster.
Health officials said that day that the child had been in isolation since August 30; as she was a household contact of an earlier confirmed case.
The link to Chapel Downs Primary, however, was only made known publicly yesterday when the school announced it had been told by authorities of the positive case about 2pm, according to principal Vaughan van Rensburg.
Given the child had been in isolation since August 30, the mandatory 14-day quarantine period finished on the Sunday before she went back to school.
The family was, however, still waiting on a test result for the little girl.
"The child and their family are in isolation - with Public Health (staff) monitoring their health and wellbeing," ARPHS said in a statement.
The first Botany case was reported on August 28 and is reportedly made up of two households.
By September 5, the sub-cluster included 42 identified contacts at that point.
Director general of health Dr Ashley Bloomfield has previously said that authorities were hopeful the Botany sub-cluster was now well contained.
"It's just that it's appeared quite late - several weeks after the first cases in this outbreak," he said.
Last Thursday, the Ministry of Health released a number of new locations of interest - where confirmed Covid-19 positive cases had visited before being identified.
Among the locations revealed was Pak'nSave Ormiston - a 4-minute drive away from Chapel Downs Primary - in Flat Bush.
An infected member of the public visited that supermarket on two occasions - firstly on Wednesday, August 26, between 1pm to 2pm and again on Friday, August 28, between 11am to 12pm.
Parents and staff at Chapel Downs have been sent letters from the ARPHS informing them of the situation and letting them know that they are working to find close contacts as quickly as possible.
"These close contacts will receive further advice on self-isolation and testing," a statement said.
Children at other schools with siblings at Chapel Downs urged to stay home
There are several schools - including early childhood education centres, primary, intermediate and secondary schools - around the affected school.
A number of those campus have sent messages to parents and its respective school communities urging any students with siblings at Chapel Downs to stay home until further notice.
Nearby Super Kids Learning Centre said they had a number of students who had siblings at the primary school affected and confirmed those children had been asked not to come into the centre.
A staffer told the Herald they remained open and were taking all necessary precautions to keep everyone safe.
"We are doing screening every day - including temperature checks and limiting parents and visitors who come into the centre," she said.
Kia Aroha College sent a message of support for those connected to Chapel Downs, but asked that anyone connected to the primary school to stay home.
Principal whaea Haley Milne wrote on the school's Facebook page: "Our love and support goes to the staff and students of Chapel Downs as they navigate this case and work to ensure that the people who were in contact with this child have been contacted and tested.
"We encourage any of our families who also have children who attend Chapel Downs to keep your children at home - including those who attend Kia Aroha as an extra precaution - and to keep all of our Kia Aroha students and families safe too."