Detectives investigating a convicted murderer are to drain a pond where his victim's boots were found.
Christopher Halliwell, 50, is serving a life sentence after pleading guilty to the murder of Swindon office worker Sian O'Callaghan in 2011.
Halliwell also told police he had killed Becky Godden, who disappeared from the Wiltshire town a decade earlier.
A judge later ruled his confession was inadmissible because top detective Steve Fulcher breached Halliwell's rights.
Wiltshire Police have continued to investigate the murder of Miss Godden, who had drifted into drugs and prostitution, and aim to bring her killer to justice. Officers found her remains in a field in Eastleach, near Cirencester, Gloucestershire, in March 2011, having been led there by Halliwell.
A bone belonging to Miss Godden was discovered at the Cotswold beauty spot last month.
Last week, officers began searching a pond in Ramsbury, Wiltshire and discovered the boots 22-year-old Miss O'Callaghan was wearing when she disappeared.
A single barrel shotgun was also discovered in the pond. Miss O'Callaghan died from a single stab wound to the head and was not shot.
Officers from Wiltshire Police's Major Crime Investigation Team are continuing to search in and around the pond.
"The specialist dive team from Avon and Somerset will continue their efforts at the scene tomorrow when they will drain the pond and conduct further searches," a force spokeswoman said.
"Searches by police officers and cadaver dogs are also continuing. Hilldrop Lane remains closed and diversions are in place."
Following the discovery of the boots, Detective Chief Inspector Sean Memory, who is leading the investigation, said he was "open minded" as to whether there may be more victims of Halliwell, as yet undiscovered.
"I am really open minded about what we may find here over the next few days," he said.
"What I will say is when we leave here we will recover every piece of evidence we are physically able to do.
"I am leading the Becky Godden investigation and we will recover everything we can and identify who that property belongs to and I am very open minded about that."
Wiltshire Police launched a high-profile inquiry when Miss O'Callaghan, who lived with her boyfriend Kevin Reape, failed to return home after a night out.
But the failure of police to properly caution Halliwell meant confessions were ruled inadmissible.