Detectives are investigating whether a suspicious fatal house fire and a head-on crash in NSW's Hunter region may be linked.
Emergency services were called to the Raymond Terrace property about 12.30am on Saturday, following reports of an explosion and a fire.
When firefighters extinguished the blaze they found a person dead inside, NSW Police said.
It's believed the body belonged to a 76-year-old woman who lived in the suburban brick home on Rosemount Drive.
It's not known what caused the fire and explosion but police are treating it as suspicious.
Officers are investigating whether the incident is linked to a head-on crash that happened almost an hour later when a Nissan X-Trail veered into the path of a B-double truck, about 75km north of the house fire, on the Pacific Highway near Bulahdelah.
The 69-year-old male driver of the Nissan previously lived in the Rosemount Drive home, acting Superintendent Alan Jansen told reporters on Saturday.
The male was on the wrong side of the road when the crash happened and is under police guard in John Hunter Hospital with serious injuries, Supt Jansen added.
The relationship between the man and woman is being investigated.
A nearby resident described the woman as "only a little lady" who was very ill.
"She was a beautiful person," Peter Kafer told the Seven Network on Saturday.
The truck driver was uninjured in the crash.