A farmhouse is being demolished brick by brick to get to the bodies of a father and five children killed in an horrific blaze.

Demolition experts have been brought in to take down 260 tonnes of bricks and mortar before the six bodies can be recovered.

Police are still investigating what caused the fire that killed doting dad David Cuthbertson, 68, and five of his children nine days ago.

Officers have been on site examining the remains of the 200-year-old farmhouse.

One of the walls has collapsed since the fire and it is unsafe for investigators to venture inside.

Chief Supt Tony Brown said: “My primary objective is to preserve evidence while being sympathetic and caring to the family of those who died in this tragedy.

“The building is unstable and will be taken down brick by brick before we can go in there.

“At the moment is unsafe for anyone to go into the remains of the farmhouse.

“Once it is made safe we will carry out a fingertip search of the whole scene.”

Chief Supt Brown confirmed the bodies of Mr Cuthbertson and five of his children aged between four and 12 are still where they died after fire ripped through the isolated house in Llangammarch Wells, Powys, Mid Wales.

Three more of his children, two boys and a girl aged 13, 12 and 10 escaped when Mr Cuthbertson lowered them to safety from an upstairs window.

It’s thought he bravely went back for the other five when he was overcome by the heat and smoke.

Dyfed-Powys Police said the three surviving children were “traumatised” after losing their dad and five siblings in the inferno.

They are being interviewed by specially trained officers to establish the cause.

A team of 40 officers are involved in the investigation, along with forensic scientists and fire experts.

Scaffolders have been brought in to stabilise the remaining walls and a temporary roof has gone up to preserve the scene from the weather.

The work has been slowed down because asbestos was discovered in the building.

Chief Supt Brown, who has been brought in from neighbouring South Wales Police, said: “It will be slow progress. It will take some time - we are talking weeks if not months.

“There are 260 tons of bricks and mortar which will be taken down by hand.

“We’ve had top explain to the family that this process is going to take some time.

“It is very difficulty for the family - we want the best for them but I can’t put the lives of my officers at risk.

“We’ve already had a partial collapse of the building.”

The six victims will not be officially named and identified until they are recovered from the scene.

Specialist equipment has been brought in from the Metropolitan Police to help with the difficult investigation.

Chief Inspector Martin Slevin said: “At the moment the cause of this intense fire is unexplained.

“We have spoken to neighbours and there is nothing to support suspicious circumstances.”

Mr Cuthbertson was bringing up his eight children alone after his wife Seema, 44, suffered a stroke and moved to a sheltered housing unit eight miles away in Builth Wells.

It is understood he has nine grown-up children from two earlier marriages.

More than £20,000 has been raised in a Just Giving page for the family.