Detectives are appealing for information on a missing mother-of-four from Essex on the sixth anniversary of her disappearance.
Sandra Gant, 48, from Clacton, was last seen by her family on 13 November 2003.
She disappeared the next day after she and two friends went for a drink at a flat with a man they had just met.
It is thought that Ms Gant left alone on the evening of 15 November to go home, but she was not seen again and her body has not been found.
Officers have yet to obtain evidence to charge anyone with the offence.
Det Supt John Quinton, said: "We never close an unsolved case. We know there are people living in Clacton who have crucial information on Sandra's last moments and where she is now.
"The Clacton community hold the key to unlocking the mystery surrounding her disappearance and presumed death."
A teenager was arrested on suspicion of murder in December 2003 and two men and a woman were also arrested at a later date.
All four were released on police bail.
Det Supt Quinton added: "Today marks a poignant date for Sandra's family.
"We hope this appeal will strike a chord with someone and prompt them to contact us with information.
"Sandra's family continue to experience torment through the unknown."