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.

Trump says US considering 'winding down' Iran war; Natanz nuclear facility attacked
Former FBI chief Robert Mueller dies aged 81
Ukrainian shelling kills four in Russia's Belgorod, governor says
Fire at Korean car parts factory kills 14, injures 60
Ukraine says Russian attacks leave two dead, thousands without power
