The national median house price in New Zealand rose $NZ5,000 ($A3,998) from November to a December record $NZ360,000 ($A287,884) last month, but the real estate industry is concerned that the number of sales for the month failed to top 5000.
Real Estate Institute of New Zealand (REINZ) president Peter McDonald said the appreciating market was "fuelled by a shortage of properties" for sale.
"It is concerning there was less than 5,000 residential properties sold in December, but the sale time of 33 days is one of the shortest for the year, which goes to show those properties sold were well sought after," Mr McDonald said.
He considered house prices had "definitely stabilised and appear to be slightly gaining, which is a positive sign".
The median house price last month was 1.4 per cent up on November, and 9.6 per cent higher than the year ago level of $NZ328,500 ($A262,694).
The REINZ figures show 4,957 houses sold in December, 655 more than a year earlier but down 640 on December 2007. In November 6,056 houses were sold.
Despite the rise in the median price last month, the REINZ's monthly housing price index fell 0.9 per cent.
The index, considered more likely to reflect genuine property price movements, was up 2.8 per cent for the three months to December, and rose 6.4 per cent from a year earlier. House prices were 3.8 per cent below their November 2007 peak.
The index showed Auckland prices up 9.7 per cent for the year, Wellington prices up 9.5 per cent, Christchurch up 5.8 per cent, other South Island suburbs up 8.6 per cent, and other North Island suburbs up 4.2 per cent.
While house prices are rising, sections are proving less buoyant, falling 3.5 per cent in the December month and 1.9 per cent lower than a year ago, the index shows.
In Auckland the median house price was unchanged from November at $NZ470,000 ($A375,849), with 1,646 houses sold last month, compared with 2192 in November.