Forensic scientists have been asked to examine items found by specialist dogs searching for the body of a murdered woman who went missing 25 years ago.
The searches have been carried out at the former home of Caroline Graham in Portadown, Co Armagh.
The 19-year-old went missing in April 1989 and no one has ever been charged with her murder.
It is understood that no body parts have been found at the Hanover Street property, but material of potential interest drew the attention of both of the two highly trained sniffer dogs deployed in the house.
Ms Graham was living there with her boyfriend before she disappeared.
The new searches started yesterday and are expected to continue through today and into tomorrow.
The operation has been conducted under warrant but with the consent of the current owner of the property, who police do not believe has knowledge of the events of 1989.
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.
A Police Service of Northern Ireland (PSNI) spokesman said: "Detectives from Serious Crime Branch investigating the murder of Caroline Graham in 1989 have called in specialist forensic scientists to examine items in a house at Hanover Street in Portadown where Caroline had lived.
"The house was yesterday subjected to a detailed examination by two PSNI victim recovery dogs. As a result of indications by the dogs, forensic scientists have been asked to examine certain items in the property.
"The search continued today and is expected to run into a third day."
Ms Graham was originally from Newry, Co Down, but had been living in the Portadown area for around two years before her disappearance.