The Ministry of Education's annual report says the number of teacher misconduct cases referred to the Teachers Disciplinary Tribunal jumped from 51 in the year to June 2018 to 155 in the latest June year.
The jump was partly due to a 2015 law change requiring schools to report all cases of possible serious misconduct, all dismissals and all resignations of teachers who had been advised of concerns about their teaching in the previous year.
But Secondary Principals Council head James Morris said it was also partly because schools were being forced to accept teachers "at the margins" of acceptable quality because there were just not enough teachers.
"We are in a teacher shortage, and because of that you are taking a bit more of a punt with some of your applicants, and that would typically lead to teachers who might not otherwise have been getting into positions coming into positions and getting themselves into a bit of trouble," he said.
Early Childhood Council chief executive Peter Reynolds said many childcare centres were also being forced to hire people who might not have been hired if more teachers were available.
"To put it crudely, a lot of childcare centres have ended up having to recruit people that they would not normally have said yes to," he said.
"In some cases those centres are buying a problem, and the problem tends to come to fruition fairly quickly.
"The centres that are struggling, some are finding that either the centre itself or the teachers working within the centres are starting to cut corners and are just feeling the pressure, so we are starting to see referrals come from that as well."
The number of teachers being referred for misconduct is still only a small fraction of the country's 102,800 registered teachers.
The Teaching Council received 619 complaints, mandatory reports and "own-motion" referrals about misconduct in the June 2018 year, and its disciplinary tribunal found that "serious misconduct" had occurred in only 44 cases.
The council's report for the latest year is not yet published, but the Ministry of Education report says the tribunal decided on 56 cases in the year to June, up from 41 the previous year.
It said the trebling of referrals to the tribunal caused delays. Only 77 per cent of cases were decided within eight months of referral, well short of a standard of 95 per cent.
However two new deputy chairs were appointed during the year to help clear the backlog. Reynolds said several people with early childhood expertise had also been appointed to the tribunal recently to cope with preschool cases.
Two early childhood decisions issued this month were on incidents that occurred in 2017.
Another childcare teacher broke down at a tribunal hearing this month, saying she had been "waiting for this day for so long" since she was first accused of manhandling a difficult 4-year-old child in June last year.
Morris said the 2015 changes effectively "lowered the threshold" at which schools were required to report cases of possible misconduct to the Teaching Council.
"Even if you have done your own investigation in school, they will often pick that up and have another look at it, and it does tend to take a long time to get through a process," he said.
However Reynolds said the Teaching Council was right to take all misconduct cases seriously.
"Some of them are pretty hairy cases, they do deserve to be there," he said.
"The only thing that surprised me a wee bit was a recent example of a teacher who physically assaulted a child and the decision of the tribunal was to keep the identity of the teacher quiet because he had decided to embark on a new career in real estate.
"Our argument is that it's nothing to do with the teacher, it's everything to do with the child. Not naming the teacher is an appeasement to the teacher. In our view the teacher should have been named."
