A victim of the Christchurch gas explosion is fighting for his life as expert investigators probe what happened

The Greymouth man and his wife were staying at his friends' Marble Court home in the suburb of Northwood when Friday's explosion occurred.

His daughter Belinda Blanchfield has been left feeling distraught and worried.

She says at this stage they're concerned for their families... the women are "doing okay" but there are serious concerns for the men.

Her father is on life support at Christchurch Hospital.

Blanchfield has thanked everyone for their support as well as those who helped at the scene.