"It costs us far less to spend money getting kids into some other form of educational training, or back into school, than it does to lock someone up in prison after things go badly."
As at August 9, the Ministry of Education was helping 244 students back into education after their exclusion from school.
Reasons for exclusions have included continual disobedience, drugs, and physical assaults.
If a school is unable to get an excluded student enrolled elsewhere, the ministry is called in to help.
It can direct the school to take the student back, force another school to take them, or arrange distance learning or alternative education.
The longest time a student has currently been out of school during that process is 305 school days.
Schools must be open for teaching for 192 school days so the student was absent for about a year and a half.
Katrina Casey, a deputy secretary of education, said the student was aged between 12 and 15. "The ministry is actively working on this case along with other government agencies and is in the process of enrolling the student in alternative education.
"In cases like this, where there may have been one or more Child, Youth and Family interventions, involvement with the youth justice system, transience and mental health issues, the likelihood of long periods of time out of school increases."
Young people could also be shown to be out of school for long periods due to their whereabouts being unknown, the student since turning 16, or a school being slow to report their enrolment.
Principals' Federation president Phil Harding said without information on each case it was difficult to draw conclusions on the time students had been out of school. "Some of them will be perfectly understandable, and some will be terribly, terribly sad."
Principal: It's widespread
The principal of a school which refused to take back a violent pupil says many other schools face the same problem.
Paeroa Central won a battle with the Ministry of Education over an 11-year-old who assaulted a teacher.
The decile-one primary had been ordered to re-enrol the boy. But the ministry backed down and agreed to enrol him in alternative education.
The boy had a history of violence and had attended 14 schools.
Principal Janet Jones said no school wanted to exclude children but sometimes they had no option.
"What I got out of our experience was we weren't alone.
"I've had a lot of principals contact me and talk about the issues in their own schools."