In December 2020 home lending jumped to $9.6 billion, up from $9.2 billion in November, and $6.5 billion in December 2019.
The figures are yet more evidence of the surging housing market, fuelled by record low interest rates, relaxed loan to value ratio restrictions, and a shortage of listings.
Investors borrowed more than $2.4 billion, the most since May 2016, when $2.48 billion was lent to landlords.
Investors received $822 million on high LVR terms, over 70%, down from $844 million the month before, but up from just $196 million in December 2019.
First home buyers borrowed $1.68 billion in December 2020, up from $1.2 billion in December the year before.
High LVR lending to first time buyers jumped to $640 million, from $482 million the same month in the prior year.
The RBNZ data was released today, a month late, due to the central bank's data breach.
While the figures underline the soaring housing market, political pressure on the major banks is expected to cool the market in the months to come.
The Reserve Bank's new LVR rules, including its "60/5" limit for investor lending, have effectively come into play already, with the major banks requiring a 40% deposit from would-be landlords.