Rent gouging in Christchurch is continuing unabated and the government must order a freeze, NZ First says.

The party has previously appealed for action but ministers say more houses are being built and the problem will ease.

NZ First's earthquake issues spokesman Denis O'Rourke says he has evidence of a family with nine children which has been landed with a rent increase of $100 a week, taking their weekly rental to $560.

"This is irrefutable evidence that rent gouging is continuing as a result of the housing shortage in Christchurch in the aftermath of the earthquakes," he said on Wednesday.

"The family concerned will struggle to afford such an unconscionable hike in their rent."

Mr O'Rourke wants Earthquake Recovery Minister Gerry Brownlee to use his special powers granted by parliament to impose a rent freeze.

"It's high time he abandoned the pretence that the market will control home rents in Christchurch, and take overdue action."