Footage of the attack on the Al Noor mosque was broadcast live on Facebook for 17 minutes and the original version remained on the social network for around an hour.
However, after the OFLC banned the video, Christchurch resident Brian Johnston filed for a review, or appeal, of the classification as he felt the video "was not graphic, did not incite hatred and could not reasonable be considered as offensive".
He also submitted that the livestream was not real "but, rather, a drill or mock up" and therefore is not "in a real sense" violent or graphic.
He added the video was still presently being watched overseas and had been viewed by thousands, "meaning the ban is pointless".
The OFLC disputed Johnston's submissions, stating it was "not a tenable argument that the video is in some way fake, fabricated or falsified".
It submitted the video ought to be deemed objectionable because it depicted the infliction of extreme violence and cruelty, and once the shooting begins, "glorified the graphic mass murder of unsuspecting victims".
"The video has already been widely reported on in the media and any ongoing interest will likely be to those who are supportive of the attacker's actions or at risk of radicalisation," it submitted.
The board was unanimous in its decision to dismiss the request for review and confirm its classification as objectionable "because it promotes or supports, or tends to promote or support, the infliction of extreme violence and extreme cruelty".
Armed police guard the Masjid Al Noor, Deans Avenue Mosque, in Christchurch in March. Photo / File
"[The board] is satisfied that the video does more than just depict extreme violence and extreme cruelty and it celebrates and endorses the massacre of Muslims.
"There are a number of aspects of the video, discussed below, which in the board's mind clearly encourage and, indeed, celebrate in a graphic and horrific way the [alleged] slaughter of innocent Muslim men, women and children in a manner the availability of which is, without doubt, likely to be injurious to the public good."
The decision has been welcomed by Chief Censor David Shanks.
"When we made the decision we were very conscious we were imposing a limit on the freedom of expression and access to information that New Zealanders normally have - but we felt there was a clear and justifiable need to do so," Shanks said.
"Any decision that restricts New Zealander's freedoms is a significant decision. This is particularly true in this case, where so many people have been affected by the horrific and deeply tragic events that are the subject of this video.
"New Zealanders should be able to test any decision affecting their freedoms, and it is good that such a review has been able to be sought and obtained, relatively quickly in this case.
"We applied the same framework to the 'livestream video' that we had used for assessing material such as ISIS-promotional clips portraying killings and terrorist acts in the name of that cause.
"Taking that approach we were confident that the 'livestream video' was also objectionable under New Zealand law. We see it as positive that the Board has also used a similar approach to come to the same conclusion."
