The country's cyber security agency says the government's online identification service, RealMe, is being targeted by an email scam.
The agency, Computer Emergency Response Team (Cert NZ), said an email link takes users to a fake RealMe site that asks for proof of identity, such as a passport or driver's licence, to be uploaded.
A RealMe account can be used to apply for government jobs, renew passports, or update electoral roll details.
Cert NZ said a genuine RealMe email contains a "govt.nz" address.
It said anyone who has uploaded proof of their identity because of an email from a scam account should contact the Department of Internal Affairs if they have passport concerns, or the Transport Agency in relation to a driver's licence.