WELLINGTON — The Australian white supremacist who murdered 51 Muslim worshippers in last year's New Zealand mosque shootings will face survivors of his rampage during a sentencing hearing next week that is likely to see him jailed for life. 

Far-right extremist Brenton Tarrant was convicted in March of 51 murder charges, 40 of attempted murder and one of terrorism, after dropping his previous not guilty plea.

Tarrant is expected to be present at the Christchurch courthouse for the four-day sentencing hearing that begins on Monday (Aug 24) amid tight security and unprecedented reporting restrictions for media.

Some of the survivors and the families of his victims will be allowed in the courtroom for their first encounter with him since the shootings on March 15, 2019.

He has previously been screened into court via video link from a maximum security prison in Auckland, other than a brief appearance in the dock of a closed court the day after the shootings.

With wounds still raw from an atrocity that shocked New Zealand, presiding High Court judge Cameron Mander said the sentencing was an important milestone for victims.

"Finality and closure is considered by some as the best means of bringing relief to the Muslim community," he said in the lead-up to the hearing.

Many of the 60-plus people who will give victim impact statements have travelled from overseas for the sentencing, undergoing two weeks of quarantine so they can participate.

Due to coronavirus-related restrictions, hundreds more will have to observe social distancing as they view via live feeds to seven courtrooms in Christchurch, while others have been granted permission to monitor it online.

Prime Minister Jacinda Ardern said it would be a difficult week for many. 

"I don't think there's anything I can say that is going to ease how traumatic that period is going to be," she told reporters on Friday. 

"The whole process is likely to take some time, that's as it should be, people need to be heard."

Police will step up patrols around the courthouse and victim support workers will be present, with local mental health specialists on standby for referrals.

It is part of a massive logistical exercise that includes live translation of proceedings into eight languages to accommodate New Zealand's diverse Muslim community.

NO TERROR PLATFORM

Authorities are also intent on preventing Tarrant, who is representing himself after sacking his lawyers last month, from using the hearing to promote extremism.

He has tried sending coded messages previously, flashing an "OK" hand gesture used to signal white power during his first court appearance.

Justice Mander has imposed extraordinary restrictions on media to ensure that even if the 29-year-old spouts neo-Nazi propaganda from the dock it does not gain publicity.

Providing live updates — a common practice for media covering court cases — has been banned. 

Instead, Justice Mander will inform media after each court session what can and cannot be reported, with any breaches likely to result in a contempt of court charge.

"The court has a duty, particularly in the context of offending against the Terrorism Suppression Act, to ensure it is not used as a platform... (and) to prevent it being used as a vehicle for further harm," he said.

After the massacre, Ms Ardern vowed to deny the shooter any notoriety by never saying his name. 

The court restrictions highlight the sensitivity surrounding the worst mass shooting in modern New Zealand history, which prompted the government to tighten gun laws and step up efforts to curb online extremism.

Tarrant, a former gym instructor from the Australian country town of Grafton, arrived in New Zealand in 2017.

A loner and internet obsessive who frequented extremist online chatrooms, he lived by himself in Dunedin while gathering a cache of weapons and planning his killing spree, choosing the South Island city of Christchurch as his target.

Armed with an arsenal of semi-automatic weapons, he attacked the Al Noor mosque first, before moving on to the Linwood prayer centre, livestreaming the killings as he went.

His victims were all Muslim and included children, women and the elderly.

New Zealand does not have the death penalty but Tarrant faces the prospect of spending the rest of his life behind bars.

The terror and murder charges all carry life sentences, setting a minimum non-parole period of 17 years but giving the judge power to imprison without the possibility of release.

If Justice Mander exercises that power it will make Tarrant the first person in New Zealand to be sentenced to jail for the term of their natural life. AFP