Thank you for your reply. At this time, I am trying to obtain the names of his adoptive parents, not his biological parents. Yes, he was apparently legally adopted, and yes, also born in New Zealand.
As I am doing this research for a friend, I have not obtained a Death Certificate or Marriage Certificate (which is available) as it is cost prohibitive at this time.
The "story" that was passed down through my friends father, son of Ernest Wheeler, was that he was orphaned, then adopted.