Investigators do not believe Colin Law of Gordon in southeast Scotland was the victim of foul play, the Selkirk Weekend Advertiser reported. He was reported missing May 19, 1999.
"Colin, I will miss you every day for the rest of my life," his mother said in a statement made through police.
She requested that she remain unidentified.
After Law disappeared, police spent two weeks searching the Gordon Moss nature reserve, an area of marsh and woods near the village in Berwickshire. At times, officers waded through mud to their waists, The (Glasgow) Herald reported.
On the second anniversary, a new attempt was made to find the young man, with detectives re-interviewing witnesses.