It has been 50 years since toddler Sandy Davidson disappeared from his grandmother's garden in North Ayrshire.
The blue-eyed and blonde-haired three-year-old vanished on 23 April 1976 and has never been seen or heard from since.
Police Scotland has issued a fresh appeal for information and has released an image of what he may look like today.
Sandy's younger sister, Donna Davidson, has continually campaigned over the years as part of efforts to solve the mystery and is urging anyone with knowledge of what happened to come forward.
She said: "It is hard after 50 years and distressing that I still don't know what happened to my brother.
"To have no answers to what seems like a thousand questions is beyond heartbreaking.
"Sandy is very much in my thoughts and as a family we are urging anyone who can help to get in touch."
Sandy had been playing in the garden of his grandmother's house in the Bourtreehill area of Irvine along with Donna, then aged two, and the family dog.
It is thought the toddler may have left the garden to follow the pet dog.
Extensive searches were carried out, and over the past five decades there have been multiple appeals and high-profile media campaigns, but to date there has been no trace of him.
The case was even featured on an episode of TV series Missing Children: Lorraine Kelly Investigates back in 2009.
The new Police Scotland image was prepared by the force's forensic services.
Read more from Sky News:
Dad of man who vanished 12 years ago believes son was murdered
Detective Inspector Louise White said: "Sandy remains a missing person and our thoughts are very much with his family on this momentous anniversary of his disappearance.
"It is a very hard time for them.
"Someone must have seen Sandy that day and the answers his family need are out there somewhere. Someone must know something and I would urge them to contact us.
"Even the smallest piece of information could help us find out what happened to Sandy so please get in touch if you can assist.
"Anything new will be thoroughly assessed so contact us on 101 if you have anything to tell us, no matter how insignificant you might think your information is."
(c) Sky News 2026: Sandy Davidson disappearance: Police release new image of what missing toddler c
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