New allegations have emerged of mistreatment of children at Pacific Christian School in Auckland.
The Ministry of Education is taking the unprecedented step of suspending the private school's registration and closing it down because of fears for student safety.
The school, which is in Mangere and has 70 students, will shut down in two weeks.
A former teacher at an organisation providing school trips, Mani Barr, said she saw a boy from the school being severely disciplined for speaking out as she gave a presentation, several years ago.
"The teacher who was with them, who was a white woman, hit the child with either an open-handed slap across the face or a punch. I can't remember whether it was open-handed or if she had her hand in a punch clench. I was really distressed by it, actually."
Ms Barr said the boy later told her that he would be taken before the school's board and whipped.
She said she complained to the Ministry of Education about the offence.
The ministry said it had had concerns for a long time before deciding to close the school.
The school came under scrutiny last year, when an 11-year-old stabbed another child with a pair of scissors.
Ministry deputy secretary Katrina Casey dismissed accusations closing down the school was a hasty move.
"We first received an ERO report that highlighted some issues around the school in 2009," she said.
"Last year, we had major health and safety incident. A number of ex-pupils came forward with other complaints.
"We do not believe student welfare in the school is sufficiently high enough for students to remain at the school."
The ministry said four teachers had been formally warned after an investigation by police and social workers into allegations that physical discipline was used at the school.