A TV show will make a fresh appeal for information in the 34-year-old hunt for a Sussex schoolboy's murderer.

BBC Crimewatch will feature the unsolved case of 12-year-old Keith Lyon, who was stabbed to death on downland in Brighton in 1967.

Detective Inspector Bill Warner, who is leading the inquiry, was one of thousands of schoolchildren fingerprinted at the time of the murder.

He said: "I am hopeful the programme will shed new light on the case.

"Someone out there knows the truth about what happened. The burden of that knowledge must weigh very heavily on the conscience of that person. It is time Keith's murderer was brought to justice."

Mr Warner is convinced the killer or killers still live locally and that people who may know them have vital information.

Keith's 82-year-old mother Valda made an emotional plea for the public's help in catching his killer in May this year.

Keith, son of the late bandleader Ken Lyon, was murdered as he walked from his home in Ovingdean to shops at Woodingdean.

The appeal will be broadcast tomorrow at 9.05pm.