National Trust mansion which appeared in Keira Knightley film now 'a shell' after devastating fire

Clandon Park stately home is famous for its magnificent marble interiors

The burnt-out Grade I-listed Clandon Park in Surrey yesterday (Rex Features)

A stately home that had been known for its magnificent marble interiors and original 18th-century furniture has been left little more than a “shell” after it was devastated by fire.

Clandon Park, the National Trust-run mansion near Guilford in Surrey, was devastated by a blaze that raged for over 20 hours, with many of the treasures on display feared lost for ever.

More than 80 firefighters battled the blaze at the Grade I-listed house – which appeared in the film The Duchess, starring Keira Knightley – after being called to the site at 4pm on Wednesday.

The fire was eventually extinguished at 1.30pm yesterday, but the National Trust’s director general, Dame Helen Ghosh, said: “The house is now essentially a shell, most of the roof, ceiling and floors have collapsed into the bottom of the building.”

A fire-damaged entrance in its Marble Hall (Getty Images)

While the external walls are still standing, only one room was relatively untouched by the blaze. “It’s a terrible sight,” said Dame Helen. “We have saved some significant items but certainly not everything we wanted to save.” She added that, thankfully, no one had been hurt.

The interiors featured original stucco ceilings and fireplaces, and the property housed a collection of 18th-century furniture, porcelain and textiles.

Works feared to be lost include a series of Mortlake tapestries from the 1640s and six paintings by 17th-century artist Francis Barlow, the UK’s first wildlife painter.

The house has been managed by the Trust since 1956. It was one of the country’s finest examples of Palladian architecture – inspired by the Venetian designs of Andrea Palladio – and had become one of Surrey’s most popular wedding venues.

A spokesman for Surrey Fire and Rescue Service said an investigation had been launched to establish the cause of the fire. “Firefighters fought incredibly hard in difficult circumstances to save historic paintings and regimental colours that were in the burning building,” he said.

Rescued items from Clandon Park (Getty Images)

David McKinstry, conservation adviser at The Georgian Group – experts on historic houses from the period – said it was a “great loss”, adding: “It is one of the most complete examples of the architect Giacomo Leoni’s work in Britain, it is a pretty unique scholarly example of Palladianism in the 18th century.”

It was built in the 1720s for the Earl of Onslow and has been described as the Venetian architect’s “masterpiece” in the UK.

“The interiors are as important as the exterior; they were such a great attraction,” said Mr McKinstry.

“Unusually, it wasn’t hugely altered in the 19th century like with many houses built at the same time.”