This is a bell frog - either Green-and-golden Bell Frog (Litoria aurea) or Southern Bell Frog (L. raniformis). There are no native tree frogs in New Zealand.
@Osedax
Thank you, it was a long time ago and my only memory was that it house native herptiles. But I was a bit confused as I indeed did not recollect of any treefrogs in NZ.
