"A scene examination is currently underway and as part of our inquiries, police will be talking to those involved at the scene as well as any witnesses to this incident to establish what has occurred," Schmid said.
A post-mortem would take place tomorrow, police confirmed.
Northland DHB's head of mental health and addiction services, Ian McKenzie, said police, security and clinical staff were in attendance.
"An external investigation will be undertaken and the death has been referred to the coroner who will determine the cause of death.
"Our thoughts are with members of the whānau at this time."
