"The drop in sales can partially be ascribed to a fall-away in the number of property investors, following the tougher loan to value ratios introduced last November."
Kennedy continued: "The incredibly heated market of 2015/2016 was not sustainable long-term and I believe we are returning to the healthy activity levels seen in 2014.
"In the 12 months to January, we had a net gain of 71,305 migrants and of those around 65,000 have chosen Auckland as their new home. New builds are not keeping up with our growing population, so existing houses will remain sought after."
The Harcourts data is in line with information released yesterday by the Real Estate Institute, also showing an Auckland listings jump and slight price drop.
REINZ found Auckland for-sale inventory rose 20 per cent in the past year and 33 per cent in the past month alone. Instead of taking 41 days to sell, places are now taking 43 days to sell.
Auckland's median house price dipped from $805,000 in January to $800,000 last month, REINZ said.
Harcourts' Auckland property sales data