Police said Carl Adams, 70, and Tierra Mann, 35, have been missing since Dec. 19.
According to the man's daughter, April, Mann is the mother of her half-sister.
Records show the pair was last seen on Sprucewood Drive.
According to the family, Adams and his son were picked up from the John Avery Boys and Girls Club around 8:30 p.m. by Mann and her younger sister.
The son and sister were then dropped off at Sprucewood Drive around 10 p.m.; Adams and Mann left together.
Adams is described as a black male, 5' 7", and 150 pounds. He was last seen wearing an olive green jacket, blue jeans, and fishing hat.
Mann is described as a black female, 5' 3", and 100 pounds. She has short, straight black hair, brown eyes, a tattoo on her left arm, and a scar on her forehead.
They may be in a gray 2017 Toyota 4Runner.
Anyone with information on their whereabouts is asked to call Cpl. M. Richards at (919) 560-4440, ext. 29320, the Durham Police Department's Main Desk at (919) 560-4427, or 911.