Lending limits and interest rate fears have pushed million-dollar house sales down 4 per cent nationally but down 8 per cent in Auckland.
The Real Estate Institute has released data for this year's first half compared to last year's first half.
Bindi Norwell, REINZ chief executive, said the Auckland numbers showed a big drop. She blamed the Reserve Bank's loan-to-value lending restrictions and predictions of rising interest rates in the next 12 to 18 months.
"The number of properties sold around the country for more than a million dollars during the first half of 2017 decreased by 4 per cent when compared to the first six months of 2016," REINZ said.
"In the Auckland market, the number of million-dollar properties sold fell by 8 per cent (compared to H1 16). However, for the rest of New Zealand (excluding Auckland), the number of million-dollar plus property sales increased by 16 per cent," REINZ said.
Barfoot & Thompson data showed $1m-plus Auckland sales made up 47.9 per cent of the Auckland market in July, down on the 291 it sold in June. March was that agency's biggest month for million-dollar places: it sold 451 properties then, but by April sales in that high-end category fell to 247 sales.
Barfoots sold 41 $2m-plus properties last month, up on the 39 in June.
REINZ said Otago had the third highest number of $1m-plus properties for sale, the first time the region has been in the top three since the first half of 2011.
Hawkes Bay, Nelson, Taranaki, Tasman, Waikato and Wellington all had the highest number of million-dollar plus properties sold on record in this year's first half and this was only the second time Tasman and Taranaki experienced double digit sales of million-dollar properties, REINZ said.
The Manawatu/Wanganui area had its first $5m plus sale in the Ruapehu district.
Auckland had more than 50 $5m plus sales for the first time and nearly 80 per cent of these sales were in the former Auckland City Council area.