Newsroom has reported a man posted a selfie of himself outside the mosque on a far-right chat group, threatening worshipers at the mosque.
The man was wearing a face mask with a skull decal. He posted the selfie to a channel on the encrypted chat app Telegram, threatening to kill attendees at the mosque, Newsroom reported.
Anjum Rahman, founder of the Inclusive Aotearoa Collective, told Newsroom she had notified police and leaders in the Muslim community.
Rahman told Newsroom the threat was not unexpected.
"We were expecting as we lead into the one year anniversary of the attack that there would be a rise in activity, so this is totally not unexpected," Rahman said.
Rahman encouraged media outlets not to over-publicise the threat.
"On the one hand, we do not want to do publicity for these guys or create any fear among the community, but on the other hand, we do want [the community] to be on their guard and aware and for wider New Zealand to be aware that they actually need to be active and vigilant in this space."
She also told Newsroom Kiwis need to rally together in solidarity against such hatred.
"It would be really good for communities to pull together at this time and be really vocal. There needs to be a widespread response," she said.
A police spokesperson said they are aware of the threat and inquiries are ongoing.
"Police are working closely with the organisations involved and we have the common aim of ensuring the safety of our communities."
He said for "operational reasons" police would not be providing details about security matters before March 15, the first anniversary of the shooting.