The mural has appeared in the alley between Durham and Grey Streets, which is behind the Trustpower building. In it, Mr Key wears a blue tie, and a 'DON'T VOTE' shirt. It has been signed off with "Bansky".
Banksy take on Prime Minister John Key's resignation yesterday pic.twitter.com/922jPI0Lc5— Chang Hung (@ChangHung23) December 5, 2016
The art appeared after Mr Key announced his resignation as Prime Minister on Monday - and fits with Banksy's political and subversive oeuvre.
It's not the first artwork apparently by Banksy to appear in Tauranga.
The southern hemisphere's biggest collection of Banksy works is set to go on display in the local gallery - and other street art has appeared.
There's a line of paint running down the main street of Tauranga that leads to other artworks.
There's two children with a message, "big future, we love New Zealand", and a man and woman in a deep embrace while checking their phones.
However, there's no way of knowing whether these and the John Key artwork are his or not - leaving another question for Banksy, the international man of mystery.