Police are searching for a body at a cafe in Gloucester linked to the case of the missing teenager Mary Bastholm who was feared killed by Fred West.
Investigating officers expect to be at the location, which is at The Clean Plate café, for a number of weeks where the schoolgirl worked.
A production company called the police on May 7 while they were filming a documentary at the location.
Filmmakers reported how they had found possible evidence to suggest a body could be buried within the property.
In the past, people have linked the building to the disappearance of Mary Bastholm.
Mary was 15-years-old when she was reported missing on 6 January 1968 and she has never been found.
Detectives attended and the Major Crime Investigation Team has deemed that further assessments are required in order to determine whether an excavation is necessary.
Mary's disappearance had also previously been linked to serial killer Fred West, who died in prison in 1995 aged 53, and there was suspicion he was involved in her death.
‘Thoughts with Mary’s family’
Assistant Chief Constable Craig Holden said: "This could be a significant development on a case which has gained a lot of public interest over the years.
"On the basis of the information provided to us, we consider this to be new and potentially important evidence in the case of Mary Bastholm, however further detailed assessments will take place over the following few days to determine the extent of excavation needed.
"First and foremost our thoughts are with Mary’s family and we would ask that their privacy is respected at this difficult time.
"This news may understandably alarm those who work near to the premises, as well as those in the wider Gloucester community and beyond.
"The constabulary has always said any fresh evidence would be reviewed. This has happened and a focussed and proportionate investigation will now take place.”
Family Liaison Officers have now been put in place to provide support and updates to Mary’s family as enquiries continue.
"Due to the potential scale of this there will likely be some disruption to those who work nearby, and I ask for their patience and co-operation during this time,” Holden added.
"We will have local officers in the area and a visible police presence at the location possibly for a number of weeks.
"We would also encourage anyone who is affected by this news to please seek support."
Anyone who has any new information relating to the disappearance of Mary Bastholm can report this to Gloucestershire Constabulary online.