Rahimi Ahmad, 39, 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.
However, no one knows what has happened to Rahimi.
His wife, Azila, says she is waiting anxiously to hear from him.
"I just want to know he's safe, and I'm praying and hoping that he will call," she said.
"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.
But when she heard news about the shooting, she got worried about their safety.
She got a call from her friend saying her son was safe, but Rahimi was believed to be inside the mosque at the time of the shooting.
"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.
"But the friend didn't know what happened to Rahimi."
Azila said Rahimi was originally from Penang, Malaysia, and the family have been living in Christchurch for about five years.
Azila said she was at a loss on what to do.
"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."
Canterbury Malaysian Society president Sam Yau said he had been contacted by the Malaysian High Commission about Rahimi.
However, Yau said there was no confirmation yet on Rahimi's condition.
The High Commission had confirmed that at least one Malaysian was hurt and social media posts suggested another Malaysian could have been killed, according to a Malaysian newspaper The Star.
"The High Commission is in close contact with the local authorities to get further details on the victims. So far, one Malaysian is confirmed injured and currently receiving treatment at the hospital," the commission said in a tweet.