Sherlock Holmes and the curious case of the author's ruined mansion

Campaigners fighting to save Sir Arthur Conan Doyle's crumbling former home have been boosted by a High Court decision to allow a judicial review of a case that might have tested the wit of the author's most famous creation.

Undershaw, the house Conan Doyle had built at Hindhead, Surrey, was where he wrote The Hound Of The Baskervilles and many other Sherlock Holmes stories, and where he entertained friends including the Peter Pan writer JM Barrie and Bram Stoker, the creator of Dracula. After Conan Doyle sold the house in1921, it was run for many years as a hotel. However, since its acquisition by a property speculator in 2004, it has fallen into disrepair. Waverley District Council has given planning permission for the house to be divided into three separate dwellings, with a five more homes to be built in the grounds.

Stephen Fry and Conan Doyle's great-nephews are among the high-profile supporters of the Undershaw Preservation Trust, which wants the building preserved as a single dwelling. Many point to the site's tourism potential as a museum dedicated to the man whose most famous character continues to fascinate film-makers. The writer and League Of Gentlemen actor Mark Gatiss, who is also a member of the trust, is the co-creator of Sherlock, the BBC's modern-day adaptation starring Benedict Cumberbatch as Holmes, right. Its second series starts tomorrow.

Were Conan Doyle to return to his old home today, he would be distressed by the spectacle. Most of the windows, including that of the study at which he sat writing The Hound Of The Baskervilles, are either smashed or boarded-up, while gorse bushes cover the grounds. The terrace, which had a court where Conan Doyle played tennis with his children, watched from a bedroom window by his ailing wife, is now a rank grass meadow.

The Scottish author and his family occupied Undershaw from 1897 to 1907. "This was the first house he owned," said John Gibson, director of the trust and a Conan Doyle scholar. "He partly drew up the plans for its construction himself, on four acres of ground which he had cleared. It is 850ft above sea level and it was hoped the air would be beneficial to his wife Louise, who had tuberculosis."

Hindhead already had a reputation for its beauty and recuperative atmosphere, and was known as "Little Switzerland". When Bram Stoker visited Conan Doyle he was overwhelmed by the unbroken view from Undershaw across the Nutcombe Valley to the South Downs 20 miles away, describing it as "an endless sea of greenery".

Mr Gibson said Conan Doyle envisaged Undershaw "as a forest lodge surrounded by firs, like something out of Grimms' Fairy Tales. He even had elk antlers mounted on the ornamental chimneys to add an air of authenticity."