I dont know if this could help you in your search to i.d them
http://www.doc.govt.nz/conservation/native-animals/reptiles-and-frogs/reptiles-and-frogs-distribution-information/atlas-of-the-amphibians-and-reptiles-of-nz/electronic-atlas/Post.aspx
Try the moko Skink was looking around on google images and they look very alike