There are rising fears New Zealand's housing bubble could burst.
Standard & Poor's, the global credit rating agency, has put eight local banks on notice over fears the housing boom could destabilise the economy.
The rating agency says persistent current account deficits and a hot property market are threats to the New Zealand economy.
The International Monetary Fund says local housing is about 25 per cent over-valued and the Reserve Bank last week threatened to introduce restrictions on low-equity loans if they pose a "significant risk" to the system.
If those threats materialise, "banks' credit losses could rise materially, given that there was a build-up in housing prices and domestic credit over the period preceding the global financial crisis", it says.