Witnesses shielding the killer of a young hospital worker whose bones were found dumped beside a motorway were urged yesterday to break a 13-year silence.
Melanie Hall, 25, was last seen alive enjoying a night out in June 1996. But this week her remains were found near the M5 by a workman clearing vegetation.
The graduate's parents Pat and Steve Hall spoke of their "untold anguish" yesterday after police confirmed that bones found beneath five bags on a sliproad near Bristol were those of their daughter.
Speaking at Bath Police Station Mr Hall, 65, an ex-chairman of Bath City football club, said he needed to know how his "vibrant" daughter became a "bag of bones".
Mr Hall, from Bradford-on-Avon, said the killer was probably watching and urged the public to help. He said: "People out there know, they've lived with that secret for 13 years - now I'm appealing for the person who knows to come forward.
"Thirteen years ago we had a young vibrant daughter with a bright future in front of her... today we have a bag of bones discarded here on the side of a motorway.
"We desperately need to know what happened to Melanie on the night she left the nightclub in Bath. Watching this interview, probably, will be the person or persons involved in Melanie's murder - if not, people who know of the people involved.
"Someone out there has a pretty good idea what has happened to Melanie. A friend of people involved or a relative of people involved.
"Someone may have a good idea that something may not be right. I'm hoping that now that her body has been found they find that change of heart or strength of will to come forward.
"People out there know, and have lived with that secret for 13 years."
Mrs Hall added: "I feel very angry that she has been dumped on the side of the road like a sack of garbage. I'm sure I'll come to terms with that at some stage."
The psychology graduate had been on a night out with friends and her boyfriend of three weeks, Dr Philip Karlbaum, who left Cadillacs nightclub in Walcot Street "upset" after seeing her dancing with another man.
Miss Hall, who worked as a clerical officer in the orthopaedic department at Bath's Royal United Hospital where she met Dr Karlbaum, was last seen sitting on a stool near the dancefloor shortly after 1 a.m.
Thousands of nightclubbers and taxi drivers were interviewed in an investigation involving 60 officers and several searches of the River Avon, but no trace of Miss Hall was found.
Detective Superintendent Mike Courtiour, who is leading the investigation for Avon and Somerset Police, said, "We believe her body had been at the site for a significant amount of time."
After the press conference he added: "In 13 years loyalties change, relationships change. People have consciences and I hope as a result of hearing Mr and Mrs Hall today they will be prepared to come forward and help us."