The police have for the first time released what is believed to be the last known footage of Lisa Dorrian ahead of the 20th anniversary of her disappearance.
The footage was accompanied by a renewed appeal for information which is supported by a reward from the independent charity Crimestoppers.
It is one of Northern Ireland’s longest and most high-profile missing persons cases.
The 25-year-old was last seen alive on the night of February 27, 2005, at Ballyhalbert Caravan Park in Co Down.
Police believe she was murdered that night or in the early hours of the following morning.
The last known footage of Lisa in the days before her disappearance
Detective Chief Inspector Kerrie Foreman, from the Police Service’s Major Investigation Team, said: “Lisa Dorrian was a young woman – just 25 years old – when she was murdered.
“Lisa, who was from Bangor, was last seen alive on the night of Sunday 27 February 2005 at a party in Ballyhalbert Caravan Park. It’s believed she was murdered that night or in the early hours of the following morning.
“Despite hundreds of extensive search operations and thousands of lines of enquiries completed, Lisa’s body has not been found, and those responsible for her murder have not yet been held to account.
“Twenty years have now passed. That’s 20 long years of unimaginable torment for a loving family. Yet, despite their pain, they’ve never given up their search for answers and, likewise, our determination has remained steadfast.
“We’re releasing CCTV footage, along with still images. This is the last known footage of Lisa in the run-up to her disappearance. My hope is to jog memories, and to encourage anyone with information to speak up.”