A new "aged" photograph has been released of a boy who disappeared when he was 14 years old.
Andrew Gosden walked out of the family home in Doncaster on 14 September 2007.
He was spotted on CCTV arriving on a train at London's King Cross station but despite an extensive police investigation he has not been seen since.
The image shows how Andrew could look as a 26-year-old and without wearing his glasses.
Det Insp Andy Knowles, who is leading the South Yorkshire Police investigation, said he hoped the new image would "jog someone's memory".
"Andrew has now been missing 12 years and his family are understandably desperate for any answers that may help them understand what happened to their loved one," he said.
"I would also like to take this opportunity to once more appeal to Andrew directly. Andrew, know that you can contact us completely confidentially, let us know you are safe so we can reassure your family that you have come to no harm."
On the day of his disappearance Andrew skipped school and withdrew just under £200 from his bank account and bought a one-way ticket to London.
His family has commissioned their own searches, including a sonar scan of the River Thames.