Haji-Daoud Nabi ran into the line of fire to save others inside the Deans Avenue mosque.
His son Omar Nabi stood outside outside the High Court in Christchurch on Saturday holding a photo of his father.
"He jumped in the firing line to save somebody else's life and he has passed away," he said.
Ash Mohammed does not know what happened to his father and two brothers in one of the New Zealand mosques that were attacked.
Mr Mohammed pushed through police barricades in an effort to get closer to one of the mosques on Saturday morning.
A police officer stopped Mr Mohammed, who told the officer "we just want to know if they are dead or alive".
Mr Mohammed repeatedly called his relatives mobile phones that went unanswered and then appeared to have run out of battery power.
He says he has not heard from his father and brother since Friday, when they went to the mosque.
Mr Mohammed had planned to join them for prayers, but did not because he had an appointment he had with a lawyer about buying a house went late.
Forty-eight people with gunshot wounds are being treated at Christchurch Hospital.
Twelve operating theaters are being used and some patients will need multiple surgeries.
The chief executive of the Canterbury District Health Board, David Meates, says the patients range from young children to adults and the injuries range from minor to critical.
He says about 200 family members are at the hospital waiting for news about their loved ones.
A floral tribute is building on the fence of the Christchurch Botanic Gardens, while hundreds of family members wait outside the city's hospital waiting for news on their injured loved ones. See more photos here.
Brenton Harrison Tarrant faced court this morning, wearing a white prison tunic, charged with one count of murder.
The 28-year-old man grew up in the northern NSW town of Grafton, but travelled around the world with sporadic periods of time spent in New Zealand. He lived in Dunedin, a seaside city south of Christchurch.
In a rambling 74-page "manifesto" posted online before the attack Tarrant said he spent years planning in vengeance for deaths in Europe, before deciding on Christchurch three months ago.
He used five guns in the attack - two semi-automatic weapons and two shotguns. A leve action firearm was also found. They were weapons he obtained legalling, having acquired a Category A gun licence in November 2017. He began buying guns about a month last.
In the manifesto he describes himseld as an "orginary white man" from a "regular family", who parents are from Scottish, Irish and English stock. He had little interest in education, "barely achieving a passing grade", but his childhood was without any great issues.
Three people were arrested over the shootings, including Australian Brenton Tarrant.
Enquires are ongoing to establish whether the other two people arrested were directly involved with the terror attack.
A fourth person was arrested in the aftermath of the terror attack on Friday afternoon, but they were a member of the public who was armed with a gun, but with the intention of assisting police. They have since been released.
Below is a photo is the small timber house in the northern NSW town of Grafton that Brenton Tarrant grew up in.
Tarrant's family contacted police after seeing media reports of the shootings and they are helping police with their investigation.
NSW state Police Commissioner Mick Fuller said Tarrant had spent little time in Australia in the past four years.
Acting Deputy Police Commissioner Mick Willing said Tarrant was only known to police for "minor traffic matters."
Mr Tarrant allegedly made a "white power" gesture with his hand in the dock, the New Zealand Herald reports.
Mr Tarrant, who had a cut on his upper lip, was silent throughout the hearing and looked at media in the public gallery.