The ghost of William Terriss at Covent Garden Underground station

William Terriss was a star of the Adelphi melodramas. On 16 December 1897 Richard Archer Prince stabbed him at the theatre's private stage door in Maiden Lane, as he arrived for that evening's performance of Secret Service. Tour guides say his last words, heard by his leading lady Jessie Millward, were "I will come back." Ten years later, on 11 April 1907, Covent Garden station opened on the Piccadilly line. Local tradition says it stands on the site of a bakery Terriss used to visit.

November 1955. After closing time. Foreman Jack Hayden saw a tall man go into the exit and sent the booking clerk, Bill, to stop him on the stairs. There was no one there.

24 November 1955. In an ante-room off the staff mess room, Hayden saw him again. A "tall man wearing a grey suit, funny old collar and white gloves." When Hayden approached, the man vanished.

28 November 1955. It was the turn of Victor Locker, a 19 year old porter. "He stood in front of me and put his hands on my head," he said. Hayden and Ring heard a scream, and by one account Locker lost consciousness. Locker asked for a transfer, and got one.

Foreman Eric Davey, a colleague and a spiritualist, held a séance in the ante-room with a reluctant Locker present. "I got the name Ter... something, and a murder nearby," he reported. He made a psychic sketch of the spirit. Shown the sketch and photographs of William Terriss, Hayden and Locker are said to have cried "That's him" together.

Newspapers took up the story. Hayden later said he saw the figure several times over ten years. One account puts it at forty. It came in November and December, appeared near walls, and never answered when spoken to.

The ghost hunter Andrew Green, "the Spectre Inspector," recorded a new run of incidents in Our Haunted Kingdom (1973). On 24 and 27 March 1972 a station foreman and female staff saw the apparition in the main mess room. Porter Clifford heard phantom footsteps. Engineer Edward Pratt felt "the presence of an unseen person." A lift operator saw a tall figure in a waistcoat and tall hat, gone the moment the operator turned away.

Another account names the lift operator as Christopher Clifford, on a night shift in late 1972. All of a sudden there was "this big geezer," dressed Edwardian in a big old frock coat. Clifford judged him at 6ft 5in. It is the last reported sighting. When Green filmed at the station in 1973, Hayden told him emphatically: "I just know it is William."

No hoax has been alleged, and no source offers a conventional explanation. The name surfaced at a séance led by a spiritualist colleague, and the 1897 murder was already famous. The sightings came on late shifts in an empty deep-level station. The descriptions vary, from a Homburg to a top hat, from an opera cloak to a frock coat. The original 1955 press reports have not been traced online.

The Adelphi has Terriss stories of its own, from June Tripp's shaking sofa and green light in 1928 to a shadowy figure seen with his granddaughters in 1967. Channel 5 told the Covent Garden story in 2005, and Ghosts on the Underground followed on The History Channel in 2008. The station remains a fixture of London ghost walks and haunted tube maps.