New Zealand's largest electricity provider is being accused of exploiting its power for money.

A complaint has been laid with the Electricity Authority, over allegations Meridian Energy hiked up power prices on certain days - despite there being cheaper supply available.

Retailer Electric Kiwi laid the complaint.

Director Phillip Anderson claims Meridian spiked South Island electricity prices on a huge scale at the beginning of June - just because it could.

He said the company removed supply that was offered between $50 and $100, and then re-offered that at $5000.

"What Meridian has done in this case really is to use its market power to suit its own book in a way which sends inefficient price signals to consumers and to other power producers, and we don't think that's a good outcome for the New Zealand market."

But a Meridian Energy spokesman said that's absolutely not the case.

He said Meridian has worked within all market rules and behaved appropriately.

The company said it's happy to engage with the Electricity Authority, if an investigation is launched.

The Electricity Authority has confirmed it's received the allegation from Electric Kiwi.

It will meet tomorrow night to consider the allegation, and make a call on whether it will investigate further.