An Auckland-based police clan lab team were carrying out an examination of the chemicals and equipment used in the manufacture of meth that were located in the property.
Mr Harris, also known as John Boy, from Horeke, was driven by two men to the St John Ambulance station with a gunshot wound to his chest on October 18, 2016.
He was loaded into an ambulance but died at the station about 6.40am.
Nicky Bryan Dodd, 41, from Raumanga, has also been arrested after Mr Harris's death.
He is facing one charge of murder, two of wounding with intent to cause grievous bodily harm, two of unlawfully carrying a firearm, and one of perverting the course of justice. He has already appeared in the High Court at Whangarei.