Finance Minister Nicola Willis on Thursday pointed a finger at the central bank for its role in the economic contraction.
"The decline reflects the impact of high inflation on the economy," she said in a statement. "That led the Reserve Bank to engineer a recession which has stifled growth."
The weakness was spread across industries and particularly sizeable in manufacturing, utilities and construction. Household and government spending dropped in the quarter, while investment and exports also dragged.
For the year to September, output was down a steep 1.5%, the sharpest fall since the pandemic and well outside forecasts of a 0.4% dip.
Since the South Pacific island nation's population grew by 1.2% to 5.35 million in the year to September, GDP per person slid by an even larger 2.1% for the year.
The picture was complicated by substantial revisions from the statistics bureau, which revised up GDP growth over the two fiscal years to March 2024 by almost 2 percentage points.
That made the starting point for this year stronger than first thought. It also erased a recession and a long period of stagnant growth that had contributed to the fall of the former Labour government.
Analysts were still clinging to hope the worst was over for the economy, given the RBNZ had cut borrowing costs by a full percentage point this quarter.
An ANZ survey of businesses out Thursday showed a further recovery in activity in December, while confidence held near historic highs.
"The survey showed more signs of demand recovering, with the first decent lift we've seen in past activity, which is the best GDP indicator in the survey," said Sharon Zollner, head of New Zealand economics at ANZ.
"The bar for things to improve from here is clearly pretty low."
Source: Reuters