Canterbury businesses say the vandalism is costing them thousands of dollars in repairs and back-up generators.
Copper wire thieves are wearing hi-vis vests to look like legitimate lines workers in Christchurch, as repeated vandalism costs city businesses thousands.
Police have charged seven people with stealing copper wire from power lines near schools, preschools and residential streets.
The thefts began last year in the suburban red zone but have since spread to areas where the electricity is live.
He said thieves had left live powerlines hanging and cost the business thousands of dollars in fees.
I don't really get the point of it, copper wire can't be worth that much at a scrapper - especially if they're having to go to a dodgy one to make the trade. I guess its a sign of how tough some people are doing it at the moment.
The people taking down power lines wearing hi viz, but putting coils of power line into shopping carts should be a dead giveaway they aren't employees. Doubly so if they are doing it at night.
Maybe the power company needs to have someone collaborate with the police to work out where it happens and then report to the police at any time an odd power outage occurs.