A German tourist has been jailed for 10 months are being caught at Christchurch airport with thousands of images of children being sexually abused.
Markus Balzer's laptop contained more than 35,000 cartoons, all of which showed children being tortured or involved in sexual acts.
Balzer had used the images in compiling 570 electronic books.
Customs acting manager of investigations Shane Panettiere described the commercial activity around the images as "horrific".
Mr Panettiere said Customs places high priority on detecting this type of offence, and six people have been prosecuted so far this year.