The Serious Fraud Office (SFO) has laid charges against two people over what it says is about $2 million dollars worth of fraudulent invoices to Mighty River Power.
Paul Kenneth Rose, who was an electrical engineer at the Southdown power station, faces four charges of obtaining by deception and Jane Clare Rose faces two charges of obtaining by deception.
The SFO alleges Mr Rose, or companies under his control, falsely billed Mighty River Power for goods or services between 2005 and 2012.
It alleges that Ms Rose was also involved in the offending.
Might River Power investigated and referred to the matter to the Police, who then passed it on to the Serious Fraud Office.
SFO director Julie Read said this investigation resulted from observations and internal checks at Mighty River Power.
The accused will next appear in the Auckland District Court at the end of the month.