Energy costs have pushed up producer prices in the three months to June.
Statistics New Zealand says producers' input prices - the cost of goods and services at the farm gate - rose 5.6%, the largest quarterly rise since 1980.
Output prices leapt 3.5%, the largest quarterly rise in 23 years.
BNZ head of research Stephen Toplis says the increases are the result of drought-induced constraints on electricity generation, and are unlikely to continue.
Meanwhile, the Capital Goods Price index rose 1% in the June quarter, due to higher construction prices for new homes and higher prices for machinery.
