"The 'Auckland Effect' is casting a huge shadow over the residential property market as a whole as it continues to go mad.
"The fact that the average asking price in Auckland has increased 10 times faster than the rest of the country makes it clear that the NZ property market can no longer be thought of as a single market: it's Auckland on one hand and the rest of New Zealand in the other."
Mr Jeffries said Auckland's average asking price expectation had risen at an annual rate of 20.4 per cent, while outside of Auckland the rate was 3.6 per cent.
"We see that reflected in the fact that for the first time the average asking price of a typical Auckland house is now more than double the average asking price of an equivalent elsewhere in the country."
Five regions across the country reported falls in asking price expectations last month compared with 12 months ago.
The largest decline was in Manawatu, where asking prices were down 6.2 per cent, and in Otago, where asking prices were down 2.4 per cent.
The Waikato region also saw a decline.
"In recent months we've seen superb growth in Waikato as Aucklanders head to the region for cheaper property alternatives, but this month was a surprise result for average asking prices in the area which declined 4.1 per cent," Mr Jeffries said.
"We'll be keeping an eye out to see if it was a one-off blip or whether demand is easing."
Meanwhile, Taranaki and Bay of Plenty joined Auckland in posting double-digit growth.
In Taranaki, average asking prices rose by $67,500 to $368,150 over the past 12 months.
The Trade Me Property price index measures trends in the expectations of selling prices for residential property listings added to Trade Me Property by real estate agents and private sellers over the past three months.
