The mother of a Palestinian man killed in the Christchurch massacre has died of a heart attack after she came to attend his funeral.

Kamel Darwish, 38, a dairy farm worker and the married father of three young children, was killed in the Al Noor mosque. He came to New Zealand from Jordan last year to join his older brother. His wife and children had applied for a visa to join him.

His mother, Saud Abdelfattah Mhaisen Adwan, 65, died of a heart attack today, said an official from the Sydney-based Jordanian Embassy.

A family friend, Yaser Mohammad, said Darwish's mother arrived from Jordan yesterday.

"She came yesterday to attend the funeral. Apparently this morning she passed away because she couldn't put up with the sorrow and sadness of losing her son."

He said she had another son who lived here too.

"They are arranging to take the coffin back to Jordan".

Adwan is one of several relatives of those shot in the massacre to suffer a heart attack in the following days.

Mohsin Al-Harbi, 61, originally from Saudi Arabia, survived the initial attack, only to die in hospital.

His wife Manal was so distressed as she searched for him that she collapsed with a heart attack and was taken to hospital in a critical condition.

Sazada Akhter was seriously injured after being shot twice at Al Noor and her mother in Bangladesh was hospitalised after having a heart attack when she found out what had happened to her daughter.

Further tragedy struck the South Otago Muslim community on Wednesday when one of its members died in a crash while returning from helping relatives affected by the Christchurch terror attacks.

Mohamed Elmi, 49, was killed in a crash near Palmerston.