The principal of Papatoetoe High School says a number of students have made a "conscious choice" to refuse testing and instead undertake 14 days of isolation.
Four students at the school have contracted COVID-19, including one of the first cases in the cluster, Case A, who tested positive on the weekend of February 13 and 14 along with their parents.
The source of Auckland's current outbreak, which currently stands at 11 cases, is currently unknown. However, the latest cases - another Papatoetoe High School student, Case I, and her two siblings, Cases J and K - have now been genomically linked to the original trio.
The school is now at the centre of the outbreak, with all students and staff asked to isolate and undergo testing last week. Following the detection of Case I on Tuesday, health officials have requested students and staff to seek a second test.
Speaking to The AM Show on Wednesday morning, principal Vaughan Couillault said he was aware of a "number of students" who had made a "conscious choice" to isolate instead of getting tested for the virus.
"There's all manner of reasons why people do or don't comply with advice and requests," Couillault said.
"In some cases, I know there's a number of students where it's a conscious choice and they're choosing to isolate for that 14-day period.
"You're allowed to make that conscious decision to isolate yourself, that's all good - but we need to know what's happening."
Other students yet to be tested have proved difficult to reach, Couillault said, due to changes in contact details that were not communicated to the school.
"[For] others… the cell phone numbers have changed… we've got quite a dynamic contact list in our community," he said.
"Often there's quite a lot of change to that, that we aren't notified about. It's situations like this where the really hard-to-reach cases come to the surface."
People are entitled to refuse testing, a fact COVID-19 Response Minister Chris Hipkins reiterated on Tuesday. However, new arrivals - who are legally required to spend 14 days in a managed isolation facility upon entering New Zealand - must complete 28 days if they refuse routine testing.
"Ultimately when someone refuses to be tested - which people are entitled to do - they'll find that they'll be having a much longer stay in managed isolation than they necessarily needed to," Hipkins said during Tuesday's press conference.
The minister had been responding to a series of questions in relation to an Australian woman, Lucinda Baulch, who spent 28 days in a Wellington facility after refusing to be swabbed.
He confirmed that under New Zealand's border restrictions, new arrivals who decline to be tested are able to leave isolation after 28 days at the discretion of clinicians.
"In this particular case, if the woman concerned gets a clean bill of health and is deemed by health clinicians to be COVID-free, then she will be able to leave after 28 days - which I understand is today. It's probably twice as long as it needed to be," Hipkins said.
Newshub has asked the Ministry of Health for an explanation regarding the apparent inconsistency between the border regulations and the students' arrangements.