Far-right extremist groups shared the banned video of the March 15 terror attack on social media on the anniversary of the mass shooting.
Photo: RNZ / Eden Fusitu'a
The extremists celebrated the one-year anniversary, praising the gunman as a saint.
The full video of the attacks was posted alongside motifs of the accused gunman.
Fifty-one people died and scores more were injured in the attack.
A police spokesperson said they are working to build an in-depth knowledge of groups or individuals who may pose a threat to New Zealand.
"However we will not discuss specific individuals/groups or their tactics."
The video of the mosque attacks and a manifesto published by the accused gunman have been deemed objectionable by the Chief Censor.
People who are knowingly in possession or sharing objectionable material face a possible prison sentence.
"We would encourage anyone who becomes aware of the video being shared on social media (or other platforms) to report it to police immediately."
Photo: RNZ / Eden Fusitu'a