The Brown Lady of Raynham Hall photograph

Raynham Hall stands near Fakenham in Norfolk. It was built between 1619 and 1637 for Sir Roger Townshend, and William Kent later remodelled the interior, painted staircase included. The house had a ghost long before it had a photograph. The Brown Lady, traditionally said to be Lady Dorothy Townshend, born Walpole.

Christmas 1835. Colonel Loftus and a guest named Hawkins saw a woman in a dated brown dress. On a second sighting Loftus was drawn to her empty eye-sockets, dark in the glowing face. In 1836 the novelist Captain Frederick Marryat met her in a corridor, a lighted lamp at her features, and fired a revolver into her face before the figure instantly disappeared. In 1926 the Townshend heir and a friend met a lady on the staircase. They could see the stairs through her.

19 September 1936. About 4 pm. Captain Hubert C. Provand and an assistant working as Indre Shira were photographing the main staircase for Country Life. One plate was already exposed. Provand was focusing for a second.

Shira stood just behind the camera, flash pistol in hand, looking directly up the staircase. "All at once I detected an ethereal veiled form coming slowly down the stairs." Shira called out sharply: "Quick, quick, there's something." Provand removed the lens cap, Shira fired the flash, and Provand emerged from the focusing cloth asking, "What's all the excitement about?" He had seen nothing, and the figure was gone.

The developed negative showed a pale, translucent, hooded figure on the stairs. Shira had arranged for an independent witness, the chemist Benjamin Jones, to watch the plate develop. Jones swore the figure was there. Country Life printed the photograph and the photographers' account on 26 December 1936. Life reprinted it on 4 January 1937.

Harry Price interviewed the pair and examined the negative. "I will say at once I was impressed," Price said. "Only collusion between the two men would account for the ghost if it is a fake. The negative is entirely innocent of any faking."

The Society for Psychical Research looked too. A report by G.V.C. Herbert, dated 14 January 1937, suggested light leaking through the old camera's bellows, or shake during an exposure of about six seconds. Its verdict: "There is almost certainly a mundane explanation of the 'spectral' image." The file lay forgotten until Alan Murdie found it in 2006. Tom Ruffles later argued that several of Herbert's anomalies were simply flash reflections.

Sceptics have offered many answers, including Joe Nickell's proposal of double exposure or a composite. John Fairley and Simon Welfare noted a pale line above each stair tread, and a patch of reflected light on the banister that appears twice. Others see a superimposed statue of the Virgin Mary, grease on the lens, or Shira walking down the stairs during the exposure. For John Booth's Psychic Paradoxes, Ron Wilson recreated the effect under a bed sheet. A much later Country Life piece called it "An unorthodox, yet successful publicity stunt".

No sighting at the Hall has been documented since 1936. Yet the image still sits near the top of every list of famous ghost photographs. A veiled woman on a staircase. Caught in a single flash.