A 72-year-old man has been arrested in connection with an investigation into human bones found on farmland.
The remains were discovered in a remote location near Chop Gate in North Yorkshire on 31 March.
Forensic archaeologists said the bones are male and likely to have been there for more than half a century.
North Yorkshire Police said the arrested man, from the York area, has been interviewed and released on conditional bail.
The force is working on the investigation with the Ministry of Defence, the RAF Police Forensic Team and experts from the RAF and the Army.
The death is not being treated as a homicide.
A police spokesman said work was ongoing at the empty property, in the North York Moors National Park south of Stokesley, to remove military memorabilia found in outbuildings.
He said: "It is important to stress that the discovery of historic remains and burial sites are relatively common on North Yorkshire farmland.
"Officers are keeping an open mind until more information is known, but this is not a homicide investigation."
Anyone with information that could help the investigation is asked to contact North Yorkshire Police on 101, or Crimestoppers anonymously on 0800 555111.