Rahimi Ahmad went for Friday prayers at Masjid Al Noor on Deans Avenue with his 11-year-old son as he did every week.
His son was playing outside when gunshots were heard in the mosque - another mosque-goer grabbed his hand and took him for shelter at a house next door, the New Zealand Herald reports.
However, no one knows what has happened to Rahimi, 39.
My son was playing outside, so when the shooting happened, a friend just grabbed him and took him to a Kiwi's house next to the mosque
"I just want to know he's safe, and I'm praying and hoping that he will call," his wife Azils said, the New Zealand Herald quoted her as saying.
"Rahimi has his mobile phone with him, so I'm sure he will be able to get in contact soon. But right now I don't know what's happened to him."
Rahimi went to the mosque at around 1pm with his son, she said.
She worried when she heard news about the shooting. She got a call from her friend saying her son was safe, but Rahimi was believed to be inside the mosque when the shooting occurred.
"My son was playing outside, so when the shooting happened, a friend just grabbed him and took him to a Kiwi's house next to the mosque," Azila said.
Azila said Rahimi was originally from Penang, Malaysia, and the family had been living in Christchurch for about five years.
"We are all told to stay indoors, I really don't know who to call or what else to do," she said.
"I'm just waiting and praying that I will hear from him or at least hear that he's ok."
A man from Christchurch says he was the last person to escape from a mosque alive after the attack, the New Zealand Herald reports.
Ramzan Ali said fellow Muslims were gunned down next to him as he dived out of the window of the Deans Ave mosque, on the edge of Hagley Park.
"I could say I was blessed," he told the News Zealand Herald.
Ali, 62, was at Friday prayers at the mosque, and said there were around 300 worshippers there, the New Zealand Herald reports. He said the sermon was being given when the shooting started.
"I saw people running for all the doors. To get 300 people out of the doorways was not easy, out of two doorways, because he entered through the main door, and there were two more doors on the sides."
When I looked back there were people dead on both sides of the door. I couldn't see my brother. I just hope he's alive.
He dived behind a bench, although he said his legs would have been visible.
"He just started shooting 'Bang, bang, bang'. My cousin was sitting beside me and he got hit in his leg."
The shooting stopped and restarted seven times as the shooter kept reloading ammunition, he said.
"I'm thinking, 'Oh my God, I hope he finishes his bullets. I hope he finishes them'."
Ali said he decided to run. Another man sitting near the main door gestured for him to come towards him.
"And what [the shooter] did, he shot him on his bloody chest. Right in front of me."
He dived through an already-broken window and then into Hagley Park.
"I was the last person to get out of the mosque alive."
Ali said his brother Ashraf was in the mosque and was still missing.
"When I looked back there were people dead on both sides of the door. I couldn't see my brother. I just hope he's alive."
His cousin's husband and a friend were badly injured.
Originally from Fiji, Ali moved to New Zealand in 1989 and shifted to Christchurch five years ago. He works as a halal food auditor.