Figures released by the Reserve Bank show three times as many mortgages are being approved for property investors as they are for first home buyers.
Since February, 9169 of the 28,515 mortgages approved in New Zealand went to investors.
During that period, first home buyers were approved 2783 mortgages.
Auckland mortgage broker Christine Lockie said she had seen a marked increase in the number of investors buying properties over the past few years.
"The investors are generally competing against your first home buyers," she said.
"Generally speaking, the investors are looking at the typical first home buyer homes rather than the higher priced properties - it certainly helps drive prices up for the lower-priced properties."
She said many were doing business before new tax rules come into force in October.
Labour's housing spokesperson, Phil Twyford, said fewer first-home buyers were being approved mortgages.
"They're often really struggling to get a deposit together and with the huge price increases that we've seen, people are really struggling to cope with a mortgage that size.
He said many investors felt as if they were missing out unless they were active in the heated market.