Police have said they believe a house fire which killed three people in Bolton, Greater Manchester was started after the gas supply was tampered with.
Earlier this week they said they were treating the blaze as suspicious.
It is understood one line of inquiry was that Hassan Rafie, 49, had unlawfully killed his wife before deliberately setting the fire.
Neighbours spoke of hearing an explosion from the kitchen of home shortly before flames spread throughout the property.
Police have said they are not looking for anyone else in connection with a house fire in Bolton, Greater Manchester which killed three people in the early hours of Monday.
The bodies of architect Hassan Rafie, 49, and his law student wife, Mahnaz, 48, were discovered in the blaze at the family home.
Post-mortem examinations showed Mrs Rafie died from stab wounds and Mr Rafie from smoke inhalation and burns.
Mrs Rafie's mother, Dolleh Joseph, 74, was rescued by firefighters from an upstairs bedroom but died soon after in hospital from the effects of smoke inhalation and burns.
A woman who died following a house fire in Bolton that killed two other people has been named by police.
Dolleh Joseph, 74, was rescued by fire fighters from an upstairs bedroom and taken to hospital in the early hours of yesterday morning, but was pronounced dead a short time later.
Greater Manchester Police has said the fire is being treated as suspicious.
Our thoughts go out the family and friends here. It's a tragedy what has happened here.
At this stage while the incident is being treated as suspicious, we're not looking for anyone else involved and we have not identified any suspects.
The fire service confirmed that the fire appears to have started in the kitchen area of the house. before spreading throughout the house.
A couple who live next door to the house in Bolton, who did not wish to be named, said they were woken by an explosion, which apparently came from the kitchen area of the property. They then saw smoke fill the building.
Stuart Whittle, who lives opposite, said he arrived home in the early hours to a fog of smoke.
He said: "As I got closer I could see fire engines and police cars. I didn't think anyone was in the house."
Another close neighbour, Maria Taylor, 48, said she was woken by the sound of fire engines and then heard smashing glass as firefighters broke in to gain access to the property.
A house fire which killed three people in Bolton is being treated as suspicious, Greater Manchester Police said.
A spokesman for Greater Manchester Police said that just before 2.20am, police were called by the fire service following a blaze at a house on Albert Road West, Heaton, Bolton.
A woman was taken to hospital but died a short time later of burns.
Following a search of the house, a further two bodies were discovered.
The flames have since been extinguished.
A joint investigation has now been launched A spokeswoman for Greater Manchester Fire and Rescue Service said three fire crews were sent to the scene of the blaze at the semi-detached house following a call at 2.03am.
The fire was put out but its cause is not yet known, she added.to establish how the fire started and identify the bodies.
A spokeswoman for Greater Manchester Fire and Rescue Service said three fire crews were sent to the scene of the blaze at the semi-detached house following a call at 2.03am.
The fire was put out but its cause is not yet known, she added.
An inquiry has been launched after three people died in a house fire.
Two bodies were recovered from the address in Heaton, Bolton, while a woman was taken to hospital but died a short time later from burns.
A joint investigation by Greater Manchester Police and Greater Manchester Fire and Rescue Service has been launched to find the cause of the blaze early today.
Greater Manchester Police have arrested three more men in connection with the multiple rape and sexual assault of a teenager from Bolton. In a statement police said:
Officers investigating allegations that a 15-year-old girl from Bolton was the victim of numerous sexual assaults and rapes have made a number of additional arrests.
Three men aged 21, 34 and 45 were arrested on suspicion of rape and a 24-year-old man was arrested on suspicion of child abduction.
Today's arrests mean that a total of nine men have been arrested in connection with the allegations.