Almost three years after a white supremacist opened fire on worshippers at two city mosques, victims' families will give Coroner Brigitte Windley their views on the proposed focus of the inquiry.
But the coroner must first hear an application by family lawyers for her to recuse herself from the inquiry on the grounds of apparent bias.
They want her to appoint a replacement coroner because of her previous work as a legal adviser for police and a senior investigator for the Office of the Inspector-General of Intelligence and Security.
The inquiry was opened to address any unanswered questions following the criminal investigation and prosecution process and the Royal Commission of Inquiry.
Along with the family lawyers, the coroner is due to hear from representatives of the Federation of Islamic Associations, Islamic Women's Council, St John Ambulance, Canterbury District Health Board, police, and Human Rights Commission.
The terrorist is expected to join the hearing online from Auckland Prison and make a submission through his lawyers, but will not be seen or heard himself.
The coroner has noted her duty to prevent the hearing being used as a platform to promote his ideology, causing victims further distress.
The inquiry's purpose is to establish the circumstances of the deaths and make comments or recommendations to reduce the chance of other attacks happening in similar circumstances.
The coroner has already proposed examining the initial emergency response to the shooting and whether anyone who died could have been saved with faster medical treatment.
While the terrorist's guilty plea meant families were spared the ordeal of a criminal trial, some are concerned the royal commission did not cover all the issues in sufficiently granular detail and there has been no public examination of the actions of emergency workers and hospital staff.
Family members and friends of the dead have been deeply affected by their murders, while many others have suffered life-changing injuries and mental harm.
Federation of Islamic Associations spokesperson Abdur Razzaq said the scope hearing marked a significant step in the healing process for the Muslim community.
"Core to this process are the families who have been directly impacted, the widows, the widowers and their families," he said.
"They have been waiting to find out some answers to questions that are still unresolved."
The Chief Censor has granted an exemption so interested parties and their lawyers can read the terrorist's manifesto and view the livestream footage of the massacre, both of which are classified as objectionable publications, if the coroner considers it necessary.
She is yet to decide whether an inquest will be held.
The gunman, an Australian who was radicalised online, was sentenced to life in prison without parole in 2020, on 51 counts of murder, 40 of attempted murder and one of terrorism.
He opened fire inside the Al Noor Mosque while broadcasting the attack on Facebook Live on 15 March 2019, killing 44 people, two of whom died of their injuries in hospital.
The terrorist then drove to the Linwood Islamic Centre where he shot a further seven people dead.
While the 2020 Royal Commission concluded the shooting could not have been prevented, it identified a host of failings, including a lack of proper gun licence checks and a preoccupation with Islamist extremism by counter-terrorism officials.
The government has pledged to implement all 44 recommendations.
During the criminal investigation into the masjid attacks, police gathered information about the circumstances of the deaths, which is detailed in two "evidential overview" reports.
The coroner has not publicly released some reports relevant to the inquiry out of respect for the families, including one on the medical response to the attacks by Dr John Hick and a first responder timeline prepared by police.
