Powerco is offering a reward of up to $10,000 for information leading to a conviction for copper thefts in Palmerston North.

Last month, 12 copper thefts were reported in Palmerston North and 41 across Powerco's network since May.

Anyone who can give police information leading to an arrest and conviction, with a subsequent reparation order made, will be rewarded with an amount of money equivalent to that order.

Palmerston North Senior Sergeant Phil Ward said police were working with scrap metal dealers to ensure they were alerted to people selling copper they could not adequately explain the origins of.

The price of scrap metal had risen in the past 12 months, and the number of scrap metal thefts had risen with it, he said.

Strong's Metal Recyclers owner Graeme Ellwood said copper was selling for more than $7 a kilogram; scrap metal, $200 a tonne - so it took a lot of copper to make a significant amount of money.

People selling such materials had to provide identification, fill out forms, answer questions and were filmed on CCTV, he said. It was in the firm's interests not to buy stolen metal.

Powerco health and safety manager Fiona Ewing said thieves were putting themselves and others at risk of electrocution by cutting copper wire from live electricity networks.

Thieves were removing copper from earth cables, designed to ensure the network was safe, and in doing so, were exposing the public and Powerco's field staff to risk of a serious shock or electrocution.

"Powerco's first priority is to make the network safe from the damage caused by these thieves who are looking to make a few quick bucks without any regard for the safety of the local community."

People with information about the thefts are urged to contact police.

Mr Ward said inquiries into the thefts were ongoing.

- © Fairfax NZ News