Demanding the password to travellers' cellphones and laptops is just one of the things Customs is asking for to extend their powers.
The paper on changes to the Customs Act was released yesterday afternoon.
One of the things Customs want is the explicit power to make people give them the password or encryption key to their electronic device.
Minister for Customs Nicky Wagner said the current Act was passed almost 20 years ago and needed an update.
"The current Act, passed in 1996, is based on the 1966 Act and still contains elements of 1913 Act. It's time to update the Act to ensure Customs can best serve New Zealanders."
Ms Wagner said it was important for Customs to be able to access electronic devices to stop objectionable material like child pornography and weapons designs from getting into the country.
She said the move was not about the mass surveillance of travellers, and that it would likely be a rare occurrence.
Public consultation runs until 1 May.