The Ministry of Education and principals appear to be at odds over whether schools can expel younger students.
The confusion is highlighted by the case of a woman who says her son and his 11-year-old classmates were subject to repeated and violent bullying from a fellow pupil last year.
The woman, who spoke to the Nine to Noon programme on the condition of anonymity, says she was forced to withdraw her son from the school after efforts by a support worker, psychologists, social workers and teachers failed to curb the bully's behaviour.
She says the Ministry of Education was focused on the needs of the bully.
"They said that this boy had the same rights to access education as every child in New Zealand, and that their focus was maintaining him in school.
"When we queried what effect him staying in school had on the rest of the children in the classroom, they said that they would put in support and additional resources, so that it didn't affect the other children in the class, but it did."
The ministry declined to be interviewed, but in a statement on Wednesday said students can only be excluded from school if they are enrolled at another school.
However, the head of the Principals' Federation, Peter Simpson, told Nine to Noon that primary schools can exclude children.
Mr Simpson says if the school is unable to find an alternative, it can refer the child back to the ministry who then will try and find another school which can be the school that child has been excluded from.
"I think a school who is directed to take a child back in this kind of scenario really should be standing up and saying 'This is the behaviour, these are all the things we have done'".
Mr Simpson believes suspension and exclusion of student should be a last resort.
