There are several islands in the Torres Strait that are Australian Territory, when you fill out forms it asks "are you of Aboriginal or T S I origon"
So tecnically if you found one on Thursday Island it would be a native.
but yes gex they are nice, but find a European varanid site and search and you will find they are quite problematic and very shy, most varanids are shy but some are a lot less shy than the prasi's.