Dunedin City Council-owned lines company Aurora Energy is refusing to explain how more than 5000 power poles on its network went from requiring replacement to being serviceable in a matter of months last year.

Photo: RNZ / Ian Telfer

In March last year there were 9504 power poles needing replacement - 6552 of which were condition zero, requiring replacement within three months, according to the company's own geographic information system data which has been obtained by RNZ.

By mid-November that number had mysteriously dropped to 1789 - 529 being condition zero - despite only 2250 poles being installed on the network during that period.

Questions by RNZ to Aurora - about how many red-tagged poles it replaced in that time; how many red-tagged poles were reinforced in that time; and how poles could go from needing replacement within three months to perfectly safe - all went unanswered.

Aurora, which has consistently refused requests for interviews on its network in recent weeks, again declined to be interviewed and instead supplied a statement attributable to a company spokesperson.

"Rather than go back and analyse the historical situation, what's important is the current state of network and the ongoing maintenance and renewal programme which is the subject of an independent review," the statement said.

RNZ asked if the company stood by the safety of its network, to which it replied:

"Aurora Energy is responsible for maintaining a safe and reliable network and we know there are challenges with managing and operating an aged network that at times can present a higher level of risk.

"You have asked for a yes/no answer to safety, but no one can provide an absolute guarantee that any aspect of life is risk-free."

But former employee and whistle-blower Richard Healey, who exposed the state of the network two years ago, said he believed he had the answer about what happened to the thousands of unaccounted red-tagged poles, and the safety of the network.

"They've been reconditioned by removing the red-tags with a claw hammer is my guess," he said.

"The only way to address those poles correctly is to replace them. Now Aurora have undertaken a programme of reinforcement. Now the reinforcement is particularly problematic, it means driving a steel member down beside the pole and strapping the pole to it. Unfortunately that does not return the pole to a safe condition."

The Aurora spokesperson reiterated the company would grant interviews on its network once the review was complete.

RNZ approached their owners, the Dunedin City Council, for answers.

Dunedin Mayor Dave Cull and chief executive Dr Sue Bidrose declined interview requests.

In a written statement Mr Cull said "these matters should be referred to Aurora Energy as the network owner and manager".

"I am not in a position to comment on specific details and numbers, but note that the independent review currently underway will provide a comprehensive opinion on the state of the entire network in its current state, not as it might have been."

The company has repeatedly said, through the media and privately to politicians, it would be transparent.

Mr Healey found the lack of transparency galling.

"Aurora have had two years since I went public to sort their act out," he said.

"They've had 100 years before that to sort their act out.

"The chairman of the board has assured us, on many occasions, that they have sorted their act out and that the public can be happy with the level of safety provided by the network.

"The network is in a shambolic state."

Aurora said the independent review would be complete at the end of October.