A huge fire at a Grade I listed stately home is being treated as “suspicious”.

Sixteenth-century Parnham House in Beaminster, Dorset, suffered significant damage in the blaze on Saturday morning.

Dorset Police were called by the fire service at 4.10am to reports of a large blaze at the mansion.

A police spokeswoman said: “It is not believed anyone was inside the property and there are no reports of any injuries. At this stage the cause of the fire is unknown; however, police are treating it as suspicious and an investigation is under way.”

Craig Baker, area manager for Dorset and Wiltshire Fire Service, tweeted that there were 20 pumps at the scene, as well as an aerial ladder platform and water carrier.

He added: “A devastating fire, crews have worked tirelessly. Remains a big firefighting operation!”

Fire crews remained at the scene damping down on Saturday evening.

Parnham House is described as an “exceptionally important mid-C16 house” by Historic England.

It was built for Robert Strode and Elizabeth Hody in 1522, and was renovated in the early 1800s.

Furniture designer John Makepeace bought the property in 1976 and ran his School for Craftsmen in Wood in the house. It was then bought by Michael and Emma Treichl in 2001, who carried out extensive renovation.

Detective Inspector Andrea Power, of Weymouth CID, said: “An investigation is currently under way to establish the cause and the circumstances around the blaze.

“We are treating the fire as suspicious and I would appeal to anyone who may have witnessed any suspicious activity in the area around the early hours of this morning to please contact police.”

Anyone with information is asked to contact Dorset Police online, via 101 or call Crimestoppers anonymously on 0800 555 111.