Police in Manawatū say it's only a matter of time until a thief or innocent member of the public is killed because of stolen powerlines.
Inspector Ross Grantham said so far this year about 10,000m of copper cabling had been stolen in the region alone.
He said officers had also seen instances of potentially-live wires being left hanging down and earth cables being cut.
Police encourage people, particularly living in rural areas, to join or form neighbourhood support groups and remain vigilant for suspicious activity in their area.
Powerco health and safety general manager, Julie McAvoy, said the firm's priority was to make its electricity network safe following any thefts, with repairs being made as soon as any damage was discovered.
"We take public safety incidents extremely seriously. We encourage members of the public to notify us immediately if they see anything on our electricity networks that they are concerned about regarding safety, such as wires that have noticeably been cut or wires hanging low."