The body of missing Bangor woman Lisa Dorrian may have been dumped in water, police believe.
Ms Dorrian (25) was last seen leaving a party at a caravan park in the Co Down village of Ballyhalbert, not far from her home town.
Paramilitaries linked to the Loyalist Volunteer Force (LVF) have been blamed for her disappearance last February.
Even though her body has never been recovered, PSNI detectives are now satisfied that Ms Dorrian was murdered and believe that her body may have been disposed of in water.
Even though a number of people have been questioned, no one has been charged in connection with her disappearance.
Detectives have carried out a reconstruction of her last known movements, which was broadcast last night as part of a BBC Crimewatch programme. Ms Dorrian's parents were interviewed for the programme.
Det Chief Insp Mark Dornan said: "We hope this will encourage witnesses to come forward."
Last week, a man in his 20s questioned by police was later released pending further inquiries.