The Green Party says the use of body-scanners at Auckland international airport that show unclothed images of people, is illegal.
The technology was trialled in March and April as an alternative to a physical search for any concealed objects.
Green MP Keith Locke says the Aviation Crimes Act explicitly prohibits Customs from collecting unclothed images of passengers.
Customs says the trial was conducted under the Customs & Excise Act which allows the use of imaging equipment.
