Mighty River Power says it could take legal action to recover hundreds of thousands of dollars in costs after being defrauded by an ex-engineer.
Paul Kenneth Rose was in charge of identifying equipment needed for the Southdown power station in Penrose.
He set up companies to buy parts, and sold them at an inflated price to Mighty River.
Rose was found guilty of obtaining by deception and sentenced yesterday to three years and two months in prison.
His former wife, Jane Clare Rose, received nine months' home detention.
The Crown said the losses to Mighty River were between $200,000 and $800,000, but Justice Edwards said she could not conclude what the losses were.
The company said it has not made a decision on its next move.
