DETECTIVES believe they may have pinpointed the place where Sian O’Callaghan was murdered after police divers pulled her boots out of a murky pond in a remote field 14 miles from where she was last seen alive.

The discovery of a single boot was made on Thursday in a pond along a section of Hilldrop Lane, Ramsbury, while divers later found a second boot and a shotgun, as the new investigation team followed up leads from the 2011 case.

The new lead investigator in the Becky Godden-Edwards case, Detective Chief Inspector Sean Memory, said his theory is that Sian, 22, had been killed by mini-cab driver Chris Hailliwell at the site – even though searches in the initial inquiry focused on Savernake Forest, near Marlborough.

The development comes after it was revealed former senior investigating officer, Detective Superintendent Steve Fulcher, has resigned from the force and several weeks after new evidence was found in the Becky Godden-Edwards murder case at the field in Eastleach where she was buried.

The knife used in Sian’s killing has never been found, while several of the popular office worker’s personal items, including her phone, handbag and jewellery remain lost, although police hope these latest searches could recover them.

DCI Memory believes Sian had been brought to the remote site, with telephone analysis of her phone placing her at the scene on the night of her death at around 3.30am.

Speaking at the scene yesterday he said: “I’ve reviewed both investigations and I want to push it forward. As part of my review we identified a pond that may be of interest to us somewhere in this area. In some ways we have had a bit of luck, in others we used some good investigative techniques.

“I’m pretty sure Sian was brought to this location and I cannot say she was murdered here but this is possibly a location where she may have been murdered.”

A team of 30 officers, including police divers from Avon and Somerset Police and specialist cadaver dogs from South Wales Police, will be searching the pond and a half-mile stretch of woodland nearby for several more days.

When asked about the significance of the new finds given Sian’s killer Halliwell, 50, of Ashbury Avenue, Nythe, was jailed for life in 2012, DCI Memory said it meant they knew the killer had been there.

He said: “The significance for me is this site has been visited by Chris Halliwell - it was used as a deposition site.

“It’s a really isolated location and you could not find it by chance.

“There are big gaps between Sian going missing and I know she was in this area at around 3.30am through telephony.

“Sian's family have always wondered what may have happened to her body and where she may have been taken.

“Hopefully, as I did this morning, I may be able to fill in some of those gaps about what happened to Sian in the last moments of her life.”

DCI Memory phoned Sian’s parents from the scene to tell them about the discovery of the right boot, which was made while the media were present.

“It was a difficult conversation to have with Sian’s family,” he said. “I think they came to a point where they did not think anything else would come out of it. It is quite poignant that we have found these items.”

DCI Memory said he has not spoken directly with Halliwell in prison but would do so if and when the need arose from the investigation into Becky’s death – which is thought to have happened near the end of 2002 or the beginning of 2003.

“I have not spoken to Chris Halliwell,” the 45-year-old said.

“As part of the Becky Godden investigation, if I reach a point that we need to speak to him, we will go through the proper channels and put that in place.

“He remains a suspect. There could be others involved, so I am keeping an open mind about the circumstances.”

A police spokesman said the investigation team were also keeping an open mind as to whether the single-barrelled, well-rusted shotgun was related to either inquiry.