There is uncertainty surrounding figures showing New Zealand averted a double-dip recession in 2010.
Finance Minister Bill English on Thursday conceded the economy might be in recession, even though the latest official statistics show the economy grew 0.2% in the three months to December.
Statistics New Zealand said its provisional figures show Gross Domestic Product rose 0.2% in the final three months of last year, following a contraction of 0.2% in the previous three months.
A contraction in the December quarter would meet the official definition of two consecutive quarters of contraction required for a recession.
However, damage to Statistics New Zealand's building in Christchurch following an earthquake in February meant some information usually used to compile the figures has not been included.
BNZ economist Stephen Toplis said the information unable to be retrieved relates to 20% of the economy and any revisions could be substantial.
Mr English said it is possible that when the December figures are revised it could show that the economy contracted.
Earlier, Mr English said the economy has made an "aggressive" recovery, even though in the second half of 2010 growth was flat.
He blamed slow growth in three months to December on the effect of the Canterbury earthquake in September and on households saving rather than spending.
However, he said growth of 1.5% for the whole year was a good result.
Labour Party finance spokesperson David Cunliffe said the economy is at the bottom of a rut and the worst thing the Government can do at this time is cut spending.
Manufacturing biggest contributor to growth
Statistics New Zealand said the biggest contributor to economic growth in the December quarter was an increase in manufacturing output of 2.5%.
The services side of the economy recorded no growth overall, with output in finance, insurance and business services posting the strongest increase of 0.5%.
Production in the wholesale trade and retail, accommodation and restaurant sectors fell reasonably sharply.
The New Zealand dollar rose a fifth of a cent to US74.26 cents following the announcement on Thursday.
Goldman Sachs economist Philip Borkin said the market is relieved the figure was in positive territory, but it shows how difficult 2010 was.