Patrick Gower - On Hate: Jacinda Ardern reveals she saw livestream of Christchurch terror attack

Jacinda Ardern has revealed she saw the livestream of the March 15 terror attack.

The Prime Minister was trying to use her own social media on the day, when the livestream came up in her feed.

"I didn't seek it out, I didn't look for it. It found me," she says during an interview in the documentary Patrick Gower: On Hate.

"I opened up one of the social media platforms and it was on my feed and it started playing and it took me a moment to realize what I was seeing."

When she realised what the video was, Ardern says she was "horrified" and quickly shut it down.

"Even those brief moments I remember. I can't imagine how you could make that situation any worse, but that element of it was just so brutal," she tells Gower.

"It was just hugely upsetting. I can't imagine if you had a family member who was one of the martyrs on that day, can you imagine seeing that footage?"

Unfortunately, so many of them have. Hours after the attack, Sara Qasem and her mum Siham were at Christchurch Hospital, looking for any information on her father Abdelfattah Qasem who had been at Al Noor Mosque.

"I never actively seeked out to see the video myself. People got desperate… after hours and hours and hours of waiting to see where on earth is your loved one," Sara says.

Tragically, Abdelfattah was one of the victims of the shooting.

"I saw a moment in which I believe that I recognised who I saw," Sara says.

"It was a very very brief moment and I didn't dare look again and I just remember asking everyone, 'just stop, just stop'."

Ardern tells Gower that she knew the Government needed to do something about the fact the terror attack livestream was broadcast on social media.

And just six weeks later this led to the Christchurch Call - a commitment from governments and online tech firms around the world to thwart terrorist and violent extremist content online.

Patrick Gower: On Hate is available to watch on ThreeNow.