"A large amount of methamphetamine was also located at the scene,'' a Police spokesman confirmed.
The multiple charges the four arrested people face include for possession of firearms, a significant quantity of methamphetamine and cannabis, and theft of a range of allegedly stolen items found at the property, he said.
Two men, aged 36 and 37, were arrested and face a number of burglary, firearm and drug-related charges. A 17-year-old female also faces burglary and firearm charges. They are due to appear in the Whangārei District Court on February 18.
A 38-year-old woman is due to appear in the court on February 11, also facing multiple charges including theft.
One of the men, Christopher Ngarino, had been living with Brown at the rented house for 18 months. She had described him as a friend she had been helping through health issues.
In an email sent to the school community, Brown said she was unaware criminal activities had been taking place at her home, and she had since severed her connections with the arrested man.
Waipū School's Board of Trustees chairwoman Catherine Munro reiterated yesterday the board was taking the matter seriously.
''The board continues to work closely with the Ministry of Education and New Zealand School Trustees Association so that we address it in line with best practice.
''While we work through it, Jo Brown is working offsite and our DP is acting principal.
''Our school has had wonderful staff, parent and community support and this is ensuring there is no impact on students.''
Police said that as the matter is now before the courts, they are unable to comment further on the case.
