The realestate.co.nz website says the housing market is very much a sellers' market.
It recorded that new listings of houses available for sale fell 21% in April following a 3% decline in March.
The website, on which about 95% of the houses available for sale in New Zealand are listed, says new listings are far from matching demand with sales across the country up 11%.
Nationwide, the stock of houses available for sale sank to just seven months worth, well down on the long-term average of more than 38 weeks supply.
Asking prices increased 0.5% to a record $447,275 and from March are are up 6% compared with April last year.
In Auckland and Canterbury, listings in April were up 9.3% and 0.8% respectively compared with April last year.
Even so, the number of houses available for sale in Auckland are 53% below their long-term average while Canterbury's are 47% lower.