Philip Green failed to return to his home in Sea Mills on 31 March 1970
Police have made a fresh appeal for information about the unsolved murder of a Bristol schoolboy 40 years ago.
The body of 11-year-old Philip Green was found on Shirehampton golf course after he failed to return to his home in Sea Mills on 31 March 1970.
Despite a massive police inquiry, the killer was never identified.
Now cold case detectives from Avon and Somerset Police hope the anniversary will bring forward a vital clue from the public.
Philip's body was found in woods on the golf course, where it is thought he had been searching for lost balls to clean and sell back to golfers to make some pocket money.
He had been battered to death and a broken, blood-stained oak branch was found nearby.
At the time of the murder house-to-house inquiries were made in 54 roads and thousands of statements were taken, but police remained mystified that no-one seemed to have seen Philip walking to the golf course.
Det Ch Supt Arthur Hardy of Scotland Yard's murder squad was sent from London to help Bristol Constabulary with the investigation.
He even made an appeal over the public address system at half-time at a Bristol Rovers football match to ask if any of the 17,000 crowd had seen the schoolboy cross Shirehampton Road the previous week as they travelled to a match on the night of the murder.
Det Sgt Maurice Marshall spent eight months in Bristol investigating
His assistant at the time was Det Sgt Maurice Marshall.
Now retired, he told the BBC: "Arthur and I spent eight months in Bristol before we had to reluctantly admit that no further meaningful lines of inquiry existed.
"In 30 years as a detective both as assistant and later as a senior investigating officer, I was involved in many murder inquiries in this country and abroad but this was the only one not solved."
Previous examinations by forensic scientists for DNA evidence drew a blank but items of Philip's clothing may be tested using the latest advanced techniques.
Det Con Clare Nelson, of Avon and Somerset Police Major Crime Review Team, said: "For 40 years Philip Green's family have lived with this brutal crime and have not had closure.
"Someone out there has the information that could solve this murder and provide Philip's family with the answer they need to move on.
"I am sure that over the last 40 years people's priorities have changed. I would urge anyone with information to contact us.
"It does not matter how small that piece of information is, let us decide if it is relevant."
Anyone with any information which could help the inquiry is asked to call the Major Crime Review Team on 0845 456 7000 or call Crimestoppers on 0800 555 111.