Alexander's latest mortgage adviser survey reveals that a net 5% of brokers saw fewer investor buyers in February: "Investors are starting to back away," the former BNZ chief economist said.
The data indicates that new LVR rules on investors, and a pre-emptive clampdown by the banks, are starting to take effect.
Investor activity surged at the back end of last year, with RBNZ data indicating the highest level of investor activity since 2016.
Yet the central bank's new '60/5' rule on investor lending is likely to curb activity. Most landlords will need a 40% deposit to get a mortgage.
The economist said LVRs were likely responsible for the dampened investor activity.
"This development reduces the chances that the loan to value ratio for investors will need to be changed to a deposit of 50%. But these are early days and next month and the month after, as people have had more time to digest the change, we will gain far better insights via this survey."
Alexander said recently-enforced Residential Tenancies Act changes could be another factor behind the drop in investor buying.
Despite the slowing investor trend, first home buyer activity remains solid, according to the study.
A net 19% of advisers said they had seen more FHBs in the market in February.
A net 33% of advisers noted a rise in first home buyers in the first month of the year.