A judicial inquiry into Christchurch's mosques shooting massacre began hearing evidence on Monday.
The Royal Commission inquiry will look into whether the police and intelligence services could have prevented the attacks that left 51 people dead.
"This is a critical part of our ongoing response to the attack - the commission’s findings will help to ensure such an attack never happens here again," Prime Minister Jacinda Ardern said.
A 28-year-old Australian has been charged over the attacks and is currently undergoing tests to determine if he is mentally fit to stand trial.
This comes as Prime Minister Jacinda Ardern prepared to co-host a meeting in France that seeks global support to tackle online violence.

Mediator Pakistan says US, Iran expected to sign initial deal within 24 hours
India Air Force plane crash kills all five onboard
Trump says US military strike killed leader of Venezuela's Tren de Aragua gang
Qatar rejects media report on energy production decisions
Trump says Iran war deal close as Strait of Hormuz tensions linger
Victims' families mark Air India crash anniversary with prayers and tributes
Ebola outbreak spreads to crowded displacement camp in Congo
Fire breaks out at New Zealand's Wellington airport, disrupting flights
