Another victim who is believed to have been killed by the murderer of missing nightclubber Sian O'Callaghan went missing "several years ago", detectives have revealed.
Police said they have launched a painstaking search at a new location in Gloucestershire after confirming Miss O'Callaghan's body has been recovered from an area near the village of Uffington, 15 miles east of Swindon in Wiltshire.
Detective Superintendent Steve Fulcher, who is leading the double murder inquiry for Wiltshire Police, said there is "only one" outstanding missing person on the force's records.
Officers said they had been searching a site in Northleach, across the county border, following information from the suspect about the locations of the bodies of both Miss O'Callaghan and another victim.
Mr Fulcher said: "Searches of that area continued through the night. It is a painstaking and slow process."
In a frank admission, he later added: "We do not at this stage know what we are dealing with."
He said officers were seeking more time to question murder suspect, named locally as taxi driver Christopher Halliwell.