The World Health Organisation has removed data from its website that suggested New Zealand cities' air quality was poorer than any major city in Australia and that Auckland's air pollution was on a par with Tokyo's.
In a compilation of air quality data from 1100 cities in 91 countries, reporting concentrations of health damaging "PM10" particles WHO published 2009 data it said was sourced from the Ministry of Environment which suggested air quality in Auckland, Hamilton and Wellington breached its safety guidelines.
That, however was challenged by Environment Minister Nick Smith and his ministry.
The data has been replaced by 2010 numbers which showed all New Zealand main centres within the WHO safety guidelines of no more than 20 micrograms of PM10 particles per cubic metre of air with the exception of Dunedin which had been the only compliant New Zealand city according to the previous figures.
According to the corrected data, the naturally well ventilated Wellington had the freshest air with a reading of just 11 against 21 previously.
Dunedin or "Dundedin" as it appears on the WHO's database has gone from a reading of 19 to 25.
Coordinator at WHO's department of health and the environment Carlos Dora told Radio NZ the mistake was down to human error when the data was entered into its database.
"We've already been in touch with the Ministry of the Environment and different people in New Zealand because they spotted correctly there was a mistake. We have already corrected the database we presented already our apologies."