The number of unqualified people working as school teachers has more than doubled since the Covid-19 pandemic began and three of them are principals.
The Education Ministry said payroll data showed 1832 people were working in 647 schools in early December with Limited Authority to Teach (LAT), up from 893 people in 330 schools at the same time in 2019.
Limited Authority to Teach allows former teachers and people who do not have recognised teaching qualifications to teach in schools.
The ministry said at one school more than half the teaching staff had LAT.
"The three LATs at this school all work part-time, none are full-time," it said.
At a further three schools, half the teachers were working under LAT.
"There are three schools with 50 percent of their teaching staff on a LAT. There are a total of seven LATs working across these three schools. Each of these three schools are small, (a roll of less than 100). Because the total number of teaching staff is small, it is easier for a 50 percent threshold to be reached. For example, one of these three schools has just two teaching staff, and one of these teachers is on a LAT, therefore reaching a 50 percent threshold," the ministry said.
The ministry said at three schools the principals had LAT.
"Two of these three principals are working in very small schools (less than 50 students)," the ministry said.
The Teaching Council was in charge of granting LAT.
"A principal could not be permanently appointed without a Practising Certificate so a Limited Authority to Teach (LAT) would only be provided where there were very extenuating circumstances (for example to ensure the school can remain open while a recruitment process is undertaken for a permanent principal), and for a limited period of time," the council said.
If a LAT was approved for a person acting in a principal role, the council had a process to ensure it met the very strict criteria.
The council approved 1750 LAT applications in 2022-23, up from 871 the preceding year and 1118 in 2020-21.
Principals Federation president Leanne Otene was disappointed three people leading schools were not registered teachers.
"We know that principals are the leaders of learning in their schools and a strong leader means that you've got a strong educational platform for teaching and learning and so I am disappointed," she said.
Otene said more experienced principals were leaving the profession and it was becoming harder to replace them.
"Three schools - let's hope it doesn't end up being more," she said.
Otene said the Education Ministry made it easier for schools to hire people under LAT in the first years of the pandemic when they were struggling to find relief teachers.
"Principals have had no choice but to look at the staff that they have and we're talking about their teacher aides or their para-professionals and say 'well what skills do they have, can we support them to be able to relieve when we need to' and these are in extreme emergencies or when there isn't specialist staff to support the teaching and learning," she said.
Post Primary Teachers Association acting president Chris Abercrombie said the spike in untrained teachers showed trained teachers were in short supply, especially in some subjects.
"We hear this all the time and it's particularly in those really hard-to-staff areas: hard materials, technology, science, maths, those really hard areas. So often these are potentially teachers who have retired but their registration's lapsed, their practising certificate's lapsed, but they've come back in."
He said they were doing a good job, but the increase in people working with limited authority to teach was worrying.
"Every student, every young person in Aotearoa New Zealand deserves a qualified, trained teacher in front of them. That's a really basic sort of belief that we have and these LATs have been fantastic, they've plugged gaps that we have but ideally, we'd love these people to carry on, train to become teachers and become fully registered teachers," he said.