THE mother of a woman killed by Christopher Halliwell hopes a new book linking the jailed murderer to 27 other cases leads to further police investigation.

Karen Edwards has long suspected that the taxi driver responsible for her daughter Becky's death and the death of Sian O'Callahan may have had many more victims.

The New Millennium Serial Killer book by Swindon true crime writer Beth Trueman and former police intelligence officer Chris Clark suggests that she could be right.

Following months of research, the authors have put together a detailed argument for why Halliwell might be involved in more than two dozen unsolved cases relating to missing or murdered women.

Karen feels deep sympathy for the families who have lost loved ones as she went through a similar traumatic time when Becky went missing in 2003 and remains were found in 2011.

But although she saw justice done when Halliwell was found guilty in 2012 and given a life sentence behind bars, those other families are still left without answers.

Karen said: "It's absolutely awful to think about those people who have no clarity on who is responsible for these crimes and are still searching for justice.

"I hope and pray this book opens up a door to a new investigation because his conviction did ease the pain a little, though it never fully goes away.

"When someone who was extremely precious to you has been ripped away, it leaves a hole in your heart that never heals and your life is never the same."

Since Halliwell's jailing, Karen has heard from several families who believe the killer travelled around the country and carried out other murders.

A hoard of around 60 items of women's clothing found by police in Ramsbury in 2014, which included items belonging to Sian O'Callahan, is suspected of being a possible trophy store for the killer.

Karen added: "I've had lots of worried people get in contact with me about their own daughters and heard things which tie their cases back to Halliwell, it's shocking.

"There have been descriptions and photo-fits of his face, dates that line up with when he was active, and details which match his modus operandi.

"The big picture is building up and I think Halliwell might be one of the biggest serial killers in British history.

"I hope this book highlights these connections, makes people wake up and smell the roses, and leads to other police forces sharing more information about Halliwell and these unsolved crimes.

"I bet if they all just got in the same room and talked it through, they could see whether the pieces of this huge jigsaw actually fit together.

"Good on Chris and Bethan, I take my hat off to them. I think it's going to be an incredible, informative and enlightening book, and I look forward to reading it."