"However, there are plenty that do this and pay their taxes due, and will continue to add [value] to the properties before they on-sell them."
Mr Patten did not believe the new tax would have a major impact on house prices.
"There is still going to be a shortage of properties and a number of investors have started to look outside of Auckland now which will also start to provide some relief."
QV's national monthly data showed Auckland house values rose 20.4 per cent in the past year to reach a new average value of $874,851 - up 60.1 per cent since the last peak in 2007 and up 5.6 per cent in the past three months alone.
QV home value northern operations manager Jan O'Donoghue said speculator trading patterns showed signs they thought the market could soon turn.
"Often, nothing has been done to improve these properties at all and speculators are just on-selling it and taking the capital gain.
"Rapid on-selling can be a sign that some speculators may believe we are close to reaching the top of the market and decide they have made enough profit."
There continued to be a shortage of listings and while QV was already seeing more homes coming on to the market with the start of spring, these were selling quickly.
"There is continued evidence of high levels of speculation in the Auckland market and we are seeing more examples of price taking where the same properties are selling two or three times in a one-year period."
The Super City region continued to show rapid values increases, with activity particularly high at the lower end of the market for properties under $1 million.
QV national spokeswoman Andrea Rush said supply and migration were the main market drivers.
"The upward trend in values seen in upper North Island centres near Auckland is also continuing with the Hamilton market now accelerating and values in Tauranga, Whangarei, Hastings and the Hauraki district continuing to rise."
Labour's housing spokesman Phil Twyford said the house price jump could not be blamed solely on the market.
"People are responding to the National Government's policy which is that if you want to get rich in New Zealand become a property speculator."
What was needed was a government-backed building programme to flood the market with affordable houses and a crackdown on speculators, including a ban on non-resident foreign buyers buying existing homes.
Mr Twyford said new figures released by the Reserve Bank showed an "explosion" in mortgage lending with most of the growth going to property investors.
Revolving doors
A West Auckland house has sold twice in four months with its price jumping by more than $500,000 during that time.
The three-bedroom, two-bathroom home in Alwyn Ave, Te Atatu South, was bought for $950,000 in March. It was sold in July for $1,465,000, according to QV data.
The 1022sq m property, which backs on to the Northwestern Motorway, was marketed as having "incredible panoramic views" of the harbour, Rangitoto and the city, and private access down to the water.
The Herald revealed last week that a modest three-bedroom Henderson house on Bruce McLaren Rd had been sold four times within three months, with its price rocketing by $153,000 in 13 weeks. Neighbours said the property had sat empty since July with no improvements except for professional staging.
The quick-fire sales - blamed on "changing vendor circumstances" - led to renewed warnings that rampant property speculation was shutting first-home buyers out of the market, sparking calls for a crackdown on speculators and ban on non-resident buyers.
