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.
More top news
Dame Barbara Windsor dismisses criticism that the BBC acted "as the cheerleader" in Eastenders suicide storyline.
Thursday brings better temperatures
The UK government warns people travelling to France that strikers blockading oil refineries have caused some stations to be without petrol.