In a letter sent to the school's parents and caregivers on Friday, principal Wayne Hegarty and board chairman Sturrock Saunders said they wanted to update the school community about a "sensitive matter" following concerns being raised about the conduct of a teacher at the school.
"As the matter was serious and needed to be worked through carefully, we immediately sought advice from the Ministry of Education and New Zealand School Trustees Association," the letter said.
"Oranga Tamariki and police are investigating and have made contact with those directly impacted."
The school was now acting in a liaison and support role, as well as managing its own employment process.
The school was aware it was "disconcerting" for its school community and said its key priority had been "to support and protect the privacy of any students affected by this matter and liaise with these students and families in the first instance".
It was also being careful not to "prejudice or pre-empt any official processes".
"We do hope that you also trust that we are doing everything that is needed at this time and comfortable that we will update you as we can, but this may not be for some time as it will depend on the processed being worked through by the agencies involved," the letter concluded.
Saunders confirmed in a statement that the school was working through a matter relating to a staff member.
As well as referring the matter to the police and Oranga Tamariki, it was also liaising with the School Trustees Association and the ministry to make sure the matter was handled "in line with best practice", he said.
"We can confirm the staff member concerned is on leave while the matter is worked through."
A Police spokeswoman said: "In general Police are unable to respond to queries which seek to establish whether specific individuals or organisations are, or have been, under Police investigation."
A spokeswoman for the Teaching Council said: "We are aware of the matter and are working with other agencies. We cannot comment at this time."
