Police are offering a £20,000 reward for information on what happened to a 16-year-old boy who disappeared in 1986.
Kevin Hicks, who detectives believe was murdered, went out to buy eggs for a school project in Croydon in March 1986. He was never seen again.
Detective Inspector John McQuade, from the Homicide and Major Crime Command, said: “Kevin simply disappeared that night and was never seen nor heard of again.
“We can only imagine what the intervening years must have been like for his family, years of worry and distress at not knowing what happened. Sadly, both his parents died without ever discovering the truth.
“Many enquiries have been carried out over the years but Kevin’s body has never been found but there is no evidence he is still alive. We believe Kevin must have met someone that night, been assaulted and his body disposed of.
“A substantial reward is now on offer for anyone with information leading to the discovery of Kevin’s body or the prosecution of the person or people responsible for his murder.
“I hope this will encourage anyone with information – no matter how small you think that piece of information might be – to come forward as soon as possible.”
Kevin left the family home on Sunday 2nd March 1986, heading to the shop on Sissinghurst Road in Addiscombe, Croydon.
He went to Sperrings community shop, which was a couple of minutes walk away in Lower Addiscombe Road – so close it was visible from his bedroom window.
He was seen an hour and a half later, but did not return.
DI McQuade said: “We believe Kevin must have met someone in that hour-and-a-half and that person attacked him. Perhaps the suspect didn’t mean to kill him but it is clear Kevin’s body must have then been disposed of.
“On 25 October 1996, following media appeals, someone anonymously called the Croydon Advertiser and said she knew where Kevin’s body was. We would appeal for that person to come forward and contact us again; you may have really important information for us.
“I truly believe people in the local Croydon community hold the answers to what happened to Kevin.”
And his sister Alexandra added: “Christmas is always a particularly hard time of the year, especially now both my parents are gone. It would be the best Christmas present to have Kevin back or to know what has happened to him.
“With Kevin and I being only a year and a day apart with our birthdays, the month of February is a constant reminder of not knowing where he is or what has happened to him.
“On 2 March 2017 it will be 31 years since Kevin went missing and I appeal to anyone with any information, no matter how small, to come forward and assist police with their investigation.
“Someone somewhere knows something. It is time to let go of that secret.”
Anyone with information is asked to contact the incident room on 020 8721 4005 or Crimestoppers anonymously on 0800 555 111.