Jacinda Ardern, New Zealand's prime minister, has vowed never to refer to the Christchurch mosque attacker by his name, as she said he would face "the full force of the law."

Brenton Tarrant, an Australian white supremacist, gunned down 50 worshipers at two mosques in Christchurch last week and broadcast the footage live on the internet.

He is now in police custody awaiting trial and has asked to represent himself in court, prompting concerns he will seek to use the legal system as a platform for his far-right ideology.

But Ms Ardern said she wanted to ensure that the killer did not enjoy any publicity as a result of the shooting, and that attention should instead focus on his victims. "He sought many things from his act of terror but one was notoriety," she said.

"That is why you will never hear me mention his name."

She also implored others "to speak the names of those who are lost, rather than the name of the man who took them". Relatives of the victims say they have been overwhelmed by support from New Zealanders, who have flocked to vigils in Christchurch following Friday's attack.

Janna Ezat, whose son Hussein died as he charged at Tarrant in an attempt to save lives, said he was wearing white instead of mourning black because he was so proud of him.