Twelve people became citizens of New Zealand in the last five years despite breaching the terms of the law, including undeclared serious criminal convictions.

The Citizenship Act states applicants must declare if they have spent time in prison or if they have been convicted of a crime in the last three years.

Figures obtained by the Herald under the Official Information Act showed 10 people in the last five years had been granted citizenship despite falling into the category where they must declare their convictions or pending charges.

They were later found out and had their citizenship revoked.

Two others were deprived of citizenship because they used false identities to gain it. Neither has been convicted because they were overseas when authorities discovered the fraud.

Some of the undeclared convictions included sexual assault against a minor, assault with a weapon and importing, manufacturing and distributing methamphetamine.

In another case a person was convicted of identity fraud after having applied for residency, citizenship and a New Zealand passport using a false identity. They have, however, appealed against their convictions so their deprivation candidacy is in abeyance.

Another person was charged and convicted for obtaining a false Australian passport.

In some of the cases the person had not been charged or convicted when they obtained citizenship but as long as the crime happened before the applicant was granted citizenship, the Minister of Internal Affairs can deprive them of it.

In the cases which were not discovered until the alleged offenders were out of the country, one man provided a false birth certificate. Another government provided information that cast doubt on the man's identity which sparked an investigation.

The department discovered the man's alleged mother had never had any children.

The department said 20,148 people were granted citizenship in the financial year to June 30.

Just over 270 people were denied - 38 because of criminal convictions.

(Source - Alanah May Eriksen, NZ Herald)