Police have confirmed bones found in a field include that of a man's skull.
The remains were discovered on land off Mitchell Street in the Swaithe area of Barnsley on Sunday afternoon.
The bones have been identified as human by a forensic archaeologist and police today confirmed this includes a man's skull.
Officers also said the bones had been left at the scene within the last 20 years.
Forensic experts are conducting tests at the scene, which detectives said is expected to be cordoned off for 'a number of weeks'.
A South Yorkshire Police spokeswoman said: "Due to the early stages of the investigation, further forensic examinations and analysis will need to be conducted before the age, sex and identity can be determined, and the cause of death and the length of time the bones have been in situ ascertained.
"At this time, the death is being treated as unexplained and the scene will remain in place over the next few weeks as detectives and forensic experts continue enquiries.
"There is no indication the residents at the property, next to where the discovery was made, are linked or connected in any way. They are currently assisting police with enquiries."
Anyone with information should call South Yorkshire Police on 101 or Crimestoppers on 0800 555111, quoting incident number 605 of February 4.