The Reserve Bank has reiterated that lending restrictions on Auckland property investors will help protect the health of the financial system.
In a speech in Auckland, the deputy governor of the Reserve Bank, Grant Spencer, told his audience that Auckland house prices have surged by a quarter in the past year, compared with 3 percent nationally.
Mr Spencer says investors account for 41 percent of Auckland house purchases, and half of the new lending to investors is to those with less than a 30 percent deposit.
The Reserve Bank is worried about the potential of a sharp fall in prices in Auckland's overheated housing market.
The central bank will impose tougher rules on investors from November.
It delayed its plans by a month, to allow banks more time to adapt their systems to the new regulations.