I've got a database full of New Zealand Bank Codes, but no idea where they came from.  So I can look up 02xxxx and identify that it's BNZ and some branch.  I've found that this website (which doesn't by any means look official) has a list, but I have no idea how old it is / correct.

I see that there is an official Australian body that maintains both downloadable full lists, and updates.   Does anyone have any idea how to obtain the latest list for New Zealand?