The Combermere Abbey ghost photograph (Sybell Corbet's library exposure)

Combermere Abbey stands near Burleydam, between Nantwich and Whitchurch, on the remains of a Cistercian monastery founded in 1133. In December 1891 the house was in mourning. Wellington Henry Stapleton-Cotton, 2nd Viscount Combermere, a former Colonel in the Life Guards, died in London on 1 December, aged 73. Weeks earlier he had been hit by a carriage. A relative put it plainly: "He was run over by a wagon at Knightsbridge, crossing the street, and only lived a few weeks."

Staying at the Abbey was Miss Sybell Corbet, an amateur photographer. She turned her camera on the library. The room was empty. It was winter and the light was poor, so the exposure was long. About an hour, by most accounts. She seems to have left the room while it ran. According to the Abbey, it was the afternoon of 5 December 1891. Four miles away, at St Margaret's Church, Wrenbury, the Viscount was being buried.

When the plate was developed, reportedly a year later, the library was no longer empty. In the high-backed chair on the left, said to be the Viscount's favourite, sat the transparent image of a man. As the Abbey describes it, "His head, collar and right arm on the armrest can be clearly made out." The inscription on the back of the print called the figure "legless".

His daughter, Lady Alexander Paget, studied it. "It is my father. It is just the type of collar he wore, but the features are not distinct." The household could offer no other sitter. "There was no man in the house at the time save a younger brother, and the men-servants all of whom were clean shaven."

The Society for Psychical Research published the case in its journal in December 1895. Sir William F. Barrett, a physicist and a founder of the SPR, interviewed Miss Corbet and reportedly had no doubt of her sincerity. He suspected an accident. A manservant, sitting briefly in the chair during the exposure. Later he is said to have learned that the servants were at the funeral, and that none resembled the figure. When Barrett aired the case in the Westminster Gazette, a Combermere relative wrote to correct him. "You say he had not lost his legs, but he died from an accident in which they were so much injured, he could never have used them again."

In 1926 the then Lord Combermere sent the print to Arthur Conan Doyle, who used it as a lantern slide in his lecture on spirit photography and wrote it up in Psychic Science. Conan Doyle saw only two certain points, "that the forehead is high and bald, and that there is some appearance of beard." He also doubted the date. He believed the picture was taken on a Sunday afternoon shortly after the death, not on the day of the funeral.

Sceptics still favour Barrett's answer. Anyone who sits for a moment during an hour-long exposure leaves a faint, see-through shape on the plate. Double exposure has been raised too, and reportedly ruled out. No hoax was ever proven or admitted.

This was no medium's studio portrait. It was an accidental amateur image, and that sets it apart. It is often listed beside the Brown Lady of Raynham Hall and the Tulip Staircase ghost at Greenwich among the most famous British ghost photographs. The Abbey tells the story to this day.