Statistics New Zealand says it is investigating a privacy breach involving a completed census form which ended up in the hands of a member of the public.
A census collector in the Wellington region accidentally handed over the filled-in form, which contained private details such as income while delivering census papers last week.
Statistics New Zealand says the collector is mortified by her mistake and the incident is a one-off.
It says it takes privacy breaches very seriously and anyone with concerns should contact their help line.
Census day is on Tuesday.