Reserve Bank of New Zealand governor Graeme Wheeler believes the strength of the local currency is "unjustified and unsustainable" - though he stopped short of saying the central bank would intervene in the market.

Wheeler published a statement today stressing the real exchange rate is "well above its sustainable level and also above levels justified by short term business cycle factors".

He said it is a "significant and unhelpful headwind" for the country's non-agricultural traded goods sector