Police searching for the body of a teenager murdered 23 years ago have narrowed their focus to a small row of businesses and homes.
Detectives said they believe Caroline Graham's remains may be buried under a concrete floor of one of the properties in Portadown, Co Armagh.
The 19-year-old was living with her boyfriend in Hanover Street in the town centre when she disappeared in April 1989. Police reopened the cold case earlier this year after receiving new information.
Earlier this month officers using specialist underground probes began searching waste ground and properties in Hanover Street and two other surrounding streets - Carleton Street and Church Street. The searches were suspended after two weeks when police revealed they had received another tip-off.
On Monday officers said they were now concentrating specifically on premises in Carleton Street. Police said they do not believe the current occupants of the properties have any knowledge of the events of 1989. They have appealed for any builders to come forward who may have undertaken work in the area 23 years ago.
Officers believe they may have unwittingly concreted over the buried body and may be able to help narrow the search even further. Physical searches remain suspended pending the outcome of the appeal.
"At present police are focusing attention on properties within 30-40 yards of premises in Carleton Street, which are currently being used as a taxi office," said a PSNI spokesman.
"Detectives believe Caroline's remains may be buried under a concrete floor. They are appealing to any builders who were working in Carleton Street in April 1989 to contact them."
Newry woman Miss Graham had been living in the Portadown area for around two years before she went missing. One person was arrested in connection with her murder in 2000 but no charges were brought.
Officers can be contacted on the Investigation Team's mobile 07585 228283 or by calling police on 0845 600 8000. Information can also be passed anonymously to the Crimestoppers charity on 0800 555 111.