Experts believe skeletal remains recovered from a field in Nottinghamshire could be those of a man aged between 40 and 60 years of age.
Detectives have now opened a murder inquiry and are appealing for information about socks and a shoe found at the site.
Nottinghamshire Police said evidence gathered during a three-week search of the scene, near Sutton-in-Ashfield, suggested the victim was buried there in an attempt to conceal his body.
Bones were found on 26 April by a member of the public after construction work on farmland in Coxmoor Road, prompting a police operation which saw the exhumation of further remains.
A post-mortem examination has been conducted by a team of scientists, including an anthropologist, suggesting the skeleton is that of a male between 5ft 4in and 5ft 6in tall.
DNA testing has ruled out a link with the disappearance and suspected murder of 47-year-old Robin Barrows Spencer, a local man who was reported missing in June 2004.
Officers are now awaiting the results of radiocarbon dating testing to determine when the individual died.
Appealing for information and confirming that two socks and a shoe were found at the burial site, Assistant Chief Constable Rob Griffin, of Nottinghamshire Police, said: "It is important to remember this is not just a collection of bones in a field.
"This is someone's loved one whose family will have undoubtedly been waiting many years for answers.
"At this stage we believe the man was murdered due to the injuries sustained. This includes trauma to parts of (his) skeleton, which are undergoing further analysis.
"We also believe he was buried at this site so no one could find him. It is also possible that the burial site is not the place where his murder occurred."
The murder is not one which happened recently, Mr Griffin said, adding: "We know this because it takes a number of years for the body to decompose to bone."
"Any information you may have about who this person might be, or anything you may have heard, then we would ask you to get in touch. This murder may have happened some time ago, but times have changed and so have loyalties."
Officers also addressed "rumour and speculation" about the find, stressing that there is nothing to indicate other bodies are buried at the site.
Superintendent Claire Rukas said: "This is a single grave with a single deceased person in it.
"We know the woods around Coxmoor Road are a popular walking spot. We know the discovery of human remains will be alarming, but the public have nothing to be afraid of and they are safe to use."