A Korean student allegedly stabbed Avondale College teacher Dave Warren, 49, in the back shortly before midday yesterday.
An unnamed student told the New Zealand Herald newspaper there had been an incident at the school on Monday between Mr Warren and the student now in police custody.
Racial sensitivity may have sparked the attack, he said.
The 17-year-old student who allegedly stabbed Mr Warren in the back as he wrote on a whiteboard was to appear in the Auckland District Court today on a charge of wounding with intent to cause injury.
Mr Warren, who taught Japanese, was rushed to hospital with what were initially called serious injuries although police said they were not life threatening. He was sent home last night.
The school was shut for most of the day after the incident, as shocked parents collected their children and police cordoned off the classroom where Mr Warren was stabbed.
The Korean student was found at a Blockhouse Bay house about 3km from the school, about an hour after the stabbing. He had attended the school for a few weeks.
It was understood he was living with a relative.
School principal Brent Lewis said the school today wanted to reassure students and staff.
"What we will be saying is the fact that the school is a safe community and the fact that there has been this one-off incident from a student newly arrived at the school doesn't change our feelings about our school.
"We have a very strong sense of family at Avondale College and this has been quite shocking. It has been quite out of kilter with the style of the school," he told NewstalkZB today.
Levels of violent incidents had been dropping at the school, he said.
Teaching staff were distressed at the incident but one of the nicest comments he had had yesterday was that "you are more in danger of getting a hug".
Mr Lewis knew nothing of the claim that a racial remark had triggered the attack and said international students fitted in well at the school. He told Radio New Zealand he was disappointed students appeared on television last night suggesting Mr Warren was tough on some students.
"I think that's abuse of the media to be questioning vulnerable young people in dealing with rumour."
He said the incident had caught students and staff by surprise.
"The irony is, it's a school with a very positive school spirit. They're a tremendous bunch of students, lovely staff and they get on extremely well, so for that very reason it's all the more shocking."
