Chief Censor David Shanks has labelled a video game based on the March 15 mosque attacks as "objectionable", meaning it is illegal to distribute.
Newshub Nation revealed earlier this month that the game was freely available in New Zealand. The main character was called 'Brenton Torrent', almost identical to the name of the alleged Christchurch gunman.
The game mimicked a livestream as the player goes on a shooting spree, and included direct references to the mosque attacks.
Shanks said in a statement on Thursday the video game was now banned.
"The creators of this game set out to produce and sell a game designed to place the player in the role of a white supremacist killer," Shanks said.
He said the game was made "cheaply" and "crudely".
"The game's producers will try to dress their work up as satire but this game is no joke.
"It crosses the line."
Shanks also banned a document said to have been shared by a gunman suspected of attacking a German synagogue, and killing two people earlier this month.
"These publications promote killing and terrorism and serve no positive purpose," Shanks said.
He said the message is simple.
"These are illegal, terrorist-promotional products designed to spread hate and encourage killing."