The body of missing Bangor woman Lisa Dorrian may have been dumped in water, according to the PSNI.
Details of the lead emerged as detectives prepared to make a television appeal in a bid to find witnesses to help them identify the killer.
Lisa (25) was last seen leaving a party at a caravan park in the Co Down village of Ballyhalbert on the Co Down coast.
Paramilitaries linked to the Loyalist Volunteer Force (LVF) have been blamed for her disappearance last February.
Even though her body has never been recovered detectives are now satisfied she has been murdered.
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 movements and they will be broadcast tonight as part of a BBC Crimewatchprogramme. Lisa's parents have also been interviewed as part of the programme.
PA