An expert on Fred West says he has “always believed” the serial killer had more victims - including missing teenager Mary Bastholm.
The 15-year-old’s disappearance in 1968 has long been linked to serial killer Fred West.
Earlier this month police began investigating at a cafe in Gloucester city centre after an ITV film crew working on a documentary about Fred West alerted them to possible “human remains”.
Police have since discovered six “voids” in the ground at the Clean Plate cafe - where Mary Bastholm worked and Fred West was known to visit - and detectives will now carry out excavation works.
Gloucestershire Constabulary say they have found a “blue material” which could be significant as the teenager was wearing a blue coat when she went missing.
In an interview with ITV News West Country, Fred West’s biographer Geoffrey Wansell said he hopes her remains will finally be found.
He said: “I always believed that Fred West had other victims and the most significant of the other victims was poor 15-year-old Mary Bastholm.
“Her family have suffered for 53 years. Her parents died sadly, there are siblings left.”
Watch Geoffrey Wansell's full interview with ITV News West County presenter Kylie Pentelow
He said West “would always have wanted to keep secrets” about where any other victims were.
“That’s one of the great characteristics of serial killers - they hide the bodies because that’s their last bit of power and control. It is what serial killers do,” he said.
“I hope and pray that her remains are finally discovered.”
Geoffrey Wansell is considered the country’s expert on Fred West.
In writing his book ‘An Evil Love’, he was given access to 100 hours of taped recordings.
He told ITV News West Country Mary Bastholm was his “archetypal victim” due to her age and naivety.
“He also loved bus stops and Mary was actually standing at a bus stop waiting to get on a bus to visit her new boyfriend, carrying a plastic bag with a Monopoly set in it, and she disappeared off the face of the earth,” he added.
Fred took his own life before he could face trial but police have said they may speak to Rose West, Fred’s wife, depending on what they find during the excavation.
She is currently in prison, having collaborated with her husband in the torture and murder of at least nine young women between 1973 and 1987.
Mr Wansell said: “Even if Rosemary knows, she isn’t going to tell anybody because that’s not what she does.
“She’s been in denial since her trial in 1995.”