The inquiry would look into the suspected gunman's activities, use of social media and international connections, as well as whether there was "inappropriate" priority setting in state counter terrorism resources.
In an attack broadcast live on Facebook, a lone gunman armed with semi-automatic weapons targeted Muslims attending Friday prayers in Christchurch on March 15, killing 50 worshippers and wounding dozens of people.
Dozens of representatives of governments from around the world joined New Zealand Prime Minister Jacinda Ardern at the remembrance service in Hagley Park, near the Al Noor mosque where more than 40 of the victims were killed by a suspected white supremacist during Friday prayers.
Fifty people were slaughtered by the gunman at two Christchurch mosques during the attack, including 42 who died at Al Noor. Alayedy and others say that if the door had been wide open like it typically was during Friday prayers, many more people might have escaped.
New Zealand Christchurch terror attack LIVE updates: The New Zealand police said that they have apprehended four people in connection to the attack, while one person has been charged with one count of murder.