THE mother of one of Christopher Halliwell's victims has spoken out as police dig beneath the back yard of his former home.

In the past two days, a quiet residential street in Broadgreen has been transformed into the scene of a major forensic investigation.

Wiltshire Police are not officially linking their ongoing operation with Halliwell, but records show that the 53-year-old former taxi driver lived at 96 Broad Street between 1997 and 2001.

He has since been convicted of murdering 20-year-old Becky Godden in January 2003 and 22-year-old Sian O’Callaghan in March 2011.

After being found guilty of Miss Godden’s murder at Bristol Crown Court last year, a judge handed down a rare whole life tariff meaning he will never be released.

Sian and Becky's mothers have previously spoken of their belief that Halliwell may have been responsible for more killings.

Now that a major investigation has been launched within yards of where he used to live, those worst fears are returning to the fore.

Sian’s mother, Elaine Pickford, said she was surprised at how soon this development has come about.

“I always thought there were more but I thought it would be a year not months until it came out,” she said.

“It was only in September that the legal side of Sian and Becky came to an end.

“I was surprised when I got the call that the police had information so soon.

“They must have a good reason to search and I hope it brings families of missing people closure if anything does come up.

“I don’t want to speculate on anything at the moment but I wondered why there was eight years between Becky and Sian.

“I wouldn’t say it has churned up particular emotions for me because the worst has already happened to my family.

“If there are more, I only had five days, these people have had years so I hope they get answers and closure.”

The investigation that was launched on Monday is expected to continue for a further four days.

Neighbours have spoken of their surprise at returning home from work to find the police operation under way so close to their homes.

A man whose house sits immediately next to the alleyway where the forensics officers are working said: “I was shocked. Police have not told me anything. I just heard it was about a murder from a long time ago.”

But for some long-time residents of Broadgreen the possible connection between the police activity and convicted double murderer Christopher Halliwell comes as no surprise.

“I knew him,” said a local man as he passed the scene on Tuesday morning. “When my son was out, he used to have a key and take the dog for a walk.

“It’s chilling, he used to come to my neighbour’s barbecues.”

Police teams are due to return to the scene this morning where their excavation work will continue.