An international identity thief has the birth records of eight New Zealanders.
Internal Affairs says it was alerted to someone making purchases with stolen credit cards.
It discovered someone used several identities to request Kiwis' birth records from overseas.
Registrar-General Jeff Montgomery says the birth record itself is unlikely to be useful, but it has information such as the names and birth dates of their parents, information which the fraudster would use to impersonate someone else.
He says contact centres for services often ask for information such as a mother's date of birth and information which the thief now has.