Police have arrested a 75-year-old man and seized 250 cannabis plants after a search warrant at a site near the Whanganui River.
The land had previously been the subject of an application to grow hemp.
The plot, identified as part of Operation Emerald which targets large-scale drug cultivation, was in an isolated area inland of Raetihi, near the Whanganui River and not accessible by road.
Detective Inspector Paul Baskett, Central District field crime manager, said the authority to grow hemp had expired in 2021.
“The team were able to establish good cause to suspect that cannabis was being grown up there in large tunnel houses,” Baskett said.