Fresh searches have taken place at the home of a young woman who was murdered 25 years ago.
Caroline Graham, 19, went missing from Portadown, Co Armagh, in April 1989.
Her body has never been found and no one has ever been charged with her murder.
Throughout today specially trained police victim recovery dogs were deployed at the Hanover Street home where Ms Graham lived with her boyfriend.
The search was conducted under warrant but with the consent of the current owner of the property.
Police do not believe the current occupant has knowledge of the events of 1989.
Officers said it was not possible to state how long the search would take.
Two years ago police carried out a series of digs in and around the area of Hanover Street.
The latest initiative comes just six weeks after Ms Graham's mother, Barbara, appealed for information about her daughter's murder.
Ahead of the search commencing, the officer leading the investigation, Detective Chief Inspector Peter Montgomery, said: "It is more than 25 years since Caroline was last seen and almost two years since the most recent phase of investigative activity resumed. Despite all the hurdles posed by the passage of time, I still believe that a form of closure is possible for Caroline and her family.
"Our appeals for information have been productive. In general, people have been very helpful. We are now at a point where it is appropriate to once again begin a planned search operation, primarily to locate Caroline's remains but also as an important part of the overall investigation into her murder."
Ms Graham was originally from Newry, Co Down, but had been living in the Portadown area for around two years before her disappearance.
Mr Montgomery added: "It was around Easter at the end of March 1989 and Caroline had been for a night out to the Coach in Banbridge with a girlfriend. She stayed part of the night with her friend in a hostel in Portadown but was gone in the morning.
"I have information that suggests Caroline returned to Hanover Street to get some clothes but she has not been seen since. I believe she was murdered some time later and that her remains are somewhere in Portadown."
Detectives mounted a major search operation in the nearby Carleton Street area in 2012. Areas of waste ground and parts of premises including a well were searched. A range of specialist resources were deployed including victim recovery dogs, probes, scanners, structural engineers and an underwater search team. Nothing of significance was found.
Detectives believe the key to recovering Caroline's remains and catching her killer, or killers, lies with a small group of local people.
Mr Montgomery said: "We are grateful to those members of the community who have given us information. All our enquiries lead us to believe there is more than one person who knows exactly where Caroline is buried.
"We need them to come forward and tell us exactly what they know. Whoever is responsible for Caroline's murder may have spoken to people and they may know exactly what has happened to Caroline.
"I need to speak to anyone who saw Caroline at the Coach with her friend that night. Did you pick up Caroline and her friend and drop them off in Portadown?
"Six weeks ago I appealed to two men, possibly off-duty soldiers, who gave Caroline a lift in a black Ford XR3i car that night to come forward. Although I am not treating them as suspects, they have yet to make contact. I would urge them to do so.
"I also want to hear from anyone who has any information about Caroline's murder and where her remains might be buried. Has anyone talked to you about her murder or where she is buried?
"I want to say that if you have concerns about giving evidence, please speak to me to explore what might be possible in terms of doing so. We will do everything possible to allay any concerns you might have but the most important thing is for people to come forward."
Anyone with information is asked to contact detectives on 02890 700 727 or 07585 22 82 83.