Whangārei police also investigated an incident at the Northpower substation in Ruakākā on July 10.
There was minimal damage and nothing was stolen.
Garton said police were working with power companies to prevent further offending.
“The aim is keeping our communities safe from these burglaries.”
Acts that sabotage essential infrastructure carry a maximum penalty of 10 years in prison.
Top Energy chief executive Russell Shaw condemned the break-ins yesterday, describing them as “absolute stupidity”.
He was shocked that people had potentially put their lives at risk by breaking into the Far North substations.
The theft on July 3 forced a manual shutdown that resulted in about 4500 customers losing power.
The incident was “extremely dangerous” considering that it also sabotaged the neutral earth connection, meaning the high-voltage system did not have a proper earth reference.
That created a high risk of electrocution or serious electric shock for the thieves, but also for staff working on the substation afterwards, he said.
In the second break-in, generators were damaged just before a big storm.
The damage was discovered before the storm hit.
Shaw said anyone entering a substation without proper training or protective gear was risking serious injury or death.
Anyone seeing suspicious activity near Top Energy’s substations or electricity infrastructure should call police or contact the company on 0800 867 363.
Police ask anyone with information to visit 105.police.govt.nz or call 105. Information can also be provided anonymously through Crime Stoppers at 0800 555 111.
Brodie Stone covers crime and emergency for the Northern Advocate. She has spent most of her life in Whangārei and is passionate about delving into issues that matter to Northlanders and beyond.