New Zealand Chief Censor David Shanks says his office considered whether or not to ban the alleged Christchurch gunman's manifesto based on how they had treated previous terrorist publications.
The lengthy document created by the shooter prior to his alleged attack on March 15, has been classified as objectionable by the Censor's office, along with the video which was live streamed of the attack.
Possessing a copy of either, or distributing them to other people, is now a serious crime carrying a maximum jail term of 14 years or a fine of up to $10,000.
Speaking this morning to TVNZ1's Breakfast, Mr Shanks outlined the reasoning which was applied to the decision to censor both the document and the video.
"We've got a classification Act, which sets out various criteria that we apply," Mr Shanks said.
"So, for example, when we classify a paedophile 'how to' guide, or a meth cook book, or a terrorist promotional brochure, we step through the Act in terms of whether this is presenting a harm to society, and whether this is actually actively promoting crime.
"We stepped this booklet - I don't think I would justify or credit it with the title 'manifesto' - it's a terrorist promotional booklet - we stepped that document through the same process that we have stepped previous promotional publications from the likes of terrorist organisations such as ISIS.
"Essentially what you have here is a document that's promoting a hateful ideology, but going further than that, it's talking about specific targets, it's talking about specific means, and it's talking about specific justifications for carrying out atrocities and cruelty.
"You can't stamp out abhorrent ideas through censorship - we're very clear about that - but there's a line, and that line is set when you are actively engaged and seriously engaged in persuading people to copy your lead."
Mr Shanks said it is clear the document was written in order to inspire others to carry out terrorist attacks, and that it had a specific target audience.
"People will rightfully say 'well perhaps I should be able to read this thing to try to understand what happened' - this is a very poor place to go to try to understand what happened.
"This is a specific document created for a very specific purpose and a specific audience - to create more mayhem and terrorism.
"We've got a specific document that can be particularly harmful for its intended audience in this country - and that's not everyday New Zealanders.
"Most right-thinking people will read this and not be harmed by it, not be affected by it, not be influenced by it - it's not for them, it's not for you, it's a for a target audience susceptible and vulnerable to that message - and that can be very dangerous."
Mr Shanks acknowledged that some people would inevitably cry foul and perhaps accuse the Government of trying to "cover up" what happened.
"That's a risk - that's an unavoidable risk in these situations, and when we initially reviewed the document, my initial reaction was that I don't want to give this credibility by banning it - I don't want to give this cache an attraction - but at the end of the day we have to do our job.
"We have to step this through the legal principles that we've applied before, and essentially its the responsibility of people to recognise that, and to recognise the fact that they can't spread direct hateful messages that are exhorting people to kill and commit terrorism."
The Censor's department has already received an undisclosed number of applications for exemptions to the Act, and Mr Shanks said there will be a number of people - mostly journalists, academics, researchers and analysts - who will be granted access to the document without penalty.