A FATHER and his five children died 1,000C house fire, the cause of which cannot be explained, a coroner has ruled .

Retired builder David Cuthbertson, 68, and his children, Just Raine, 11, Reef Raine, 10, Misty Raine, nine, Patch Raine, six and Gypsy Raine, four all died in the blaze but investigators do not know how it started.

The hearing was told the fire that destroyed the farmhouse where the family lived at Llangammarch Wells may have begun when embers fell from a logburner - but there were "a number of possible sources" for the blaze.

Powys coroner Andrew Barkley said he was unable to rule out that "foul play" had caused the fire.

Giving a narrative verdict, Mr Barkley said: "The fire started in the lounge but what I cannot say is what caused that fire to start.

Reef, Misty, Just, David, Gypsy and Patch each died of the inhalation of fire fumes.

"The individuals that I’ve named died from the effects of the inhalation of fire fumes following a fire at their family home. The exact cause of that fire is as yet unexplained."

Three children aged 13, 12, an 11, survived after escaping the infernoand ran to a neighbours house where they raised the alarm.

Investigators believe the fire began in the farmhouse lounge - where a stray ember may have leapt from the log burner onto nearby furniture.

But they said there were "a number of possible sources" for the deadly fire which was so hot it melted copper piping and the fire alarms.

Chief fire investigator David Hancock said: "We believe the origin of the fire to be in the downstairs lounge. We were fairly confident but it is very difficult to totally identify one particular item that was the cause of the fire.

"In that room, we found a number of possible sources - use of candles, cigarette lighter for example.

"It is possible that a spark or ember from the log burner in the room had jumped onto furnishings. There was no spark guard as such. The metal cage around the log burner served only as a child guard.

"The fire service were called at 12:11am and arrived 12:25am. By about 1:30am the building has collapsed in on itself.

"We found copper piping on the wall inside the property had melted. Copper melts at a temperature of 1085 degrees Celsius."

But Mr Hancock, an officer with Mid and West Wales Fire and Rescue, ruled out gas for starting the blaze.

He said: "We found rubber piping connected to copper piping. The rubber had simply been pulled over the copper pipes and no compression clips used. Had there been gas involved it would’ve exploded. There is no evidence of an explosion in this case.

“There was an external search afterwards. There was nothing that we found to identify the use of fireworks or anything of that nature."

Police say they are still investigating the blaze and have probed whether it was deliberately started.

Detective inspector Adam Bennetts said: "We have kept an open mind as to the causation if the fire.

"We have been very mindful of the potential of foul play but we have not been provided with any evidence that there is a third party associated with the cause of the fire."

The farmhouse was completely gutted in the blaze on October 30 last year and had to be taken apart brick-by-brick by investigators trying to establish how it started.

A fundraising page to raise money for the family has raised more than £23,500.