"It is targetted at the very small number of individuals who may be exploring white supremacist ideology. In the hands of that audience, given the status Breivik has among some extremist and the detailed 'how to' nature of the text, this document presents a real risk to the safety and security of New Zealanders."
In the decision banning the manifesto is it described as a "bloated, dense, and lengthy document that is partly a compendium of pseudo-intellectual texts that reflect a conspiratorial far-right worldview, partly a narcissistic, aggrandised autobiography, partly a tool for radicalisation, partly an instructional manual for terroristic violence, and partly a declaration of war."
Breivik is presently serving life in prison in Norway and is near-universally reviled, but is revered by many white supremacy groups who consider him a vanguard in a coming race war.
The Royal Commission of Inquiry into the Terrorist Attack of 15 March 2019 said several direct and indirect citation of Breivik in Tarrant's own manifesto - including claims he had been been blessed by the Knights Templar - were fantasy, but the Australian-born mass-murderer had drawn practical and ideological inspiration from the Norwegian.
"We see much of what the individual said about the Oslo terrorist in his manifesto and at interview as trolling and he accepted as much when we spoke to him. We do, however, consider that the individual was significantly influence by the Oslo terrorist," the commission reported in 2020.
The Commission cited Tarrant's use of steroids to quickly increase his physical strength, operational security measures to safeguards his electronic devices, legal acquisition of a firearm and training in its use at a rifle club, and timing the publishing of propaganda to coincide with the attack as tactics learned from Breivik.
"In these respects, the guidance offered by the Oslo terrorist was largely operational in nature," the Commission's report concluded.
The Commission reported a copy of the Breivik manifesto had been found amongst Tarrant's belongings. A separate report into the attacks by the Director-General of Security and Intelligence disclosed an internet address in Dunedin - where Tarrant was based at the time - had accessed the manifesto in early 2017.
The Classification Office decision was preceded by consultations with religious groups who had highlighted an apparent inconsistency given functionally similar incitement and training manual produced by Isis and Al-Qaeda had earlier been banned.
"Our consultations also raised an interesting perspective on the differential treatment of terroristic propaganda produced by the far right compared with material produced by Islamic extremists. The implication being there is a tendency to favour free speech arguments for material produced by far-right extremists compared with material produced by Islamic terrorists," the Classifications Office said in its decision.