More cases of powerline tampering in Christchurch have seen power cut to "more than 20" households two nights in a row, police say.
Police said recent incidents have occurred "close to schools, preschools, recreational facilities and residential streets".
One of them - on Disraeli Street - was caught on CCTV camera, showing two men using a shopping trolley to cart off their haul. The noise of a grinder can be heard during the theft.
"Fortunately no one has been injured at this stage, however Police remain concerned it is only a matter of time," said Senior Sergeant Roy Appley, echoing previous statements he has made over the past six months.
"Tampering with powerlines places yourself and members of the public at risk of electrocution for a small return."
Appley said power outages could have "devastating" effects on people who need it for life support and assisted breathing machines.
Suspects caught tampering with powerlines in Christchurch. Photo: NZ Police / Supplied
Police said anyone who sees suspicious behaviour around powerlines should contact them on 111 immediately, or 105 after the fact.
Earlier this year, Appley told RNZ the payoff was at best only about $10 a kilogram "and you need an awful lot of it to make a kilogram".
In March he said the fact no one appears to have been killed doing it - yet - suggested those involved had electrical skills.
The thefts began last year in the disconnected residential red zone, but have since spread to areas where the electricity is definitely live.
There has also been a rise in reported incidents involving powerlines in Hawke's Bay.