Malton Cemetery exhumation begins at midnight
The exhumation of the unidentified body of a woman found in undergrowth in North Yorkshire in 1981 is expected to begin later.
Police said a cold case review of the death might be helped by the recovery of DNA material from the body which is buried at Malton Cemetery.
A Home Office pathologist and Crime Scene Investigators will be among those involved in the operation.
Results from the DNA tests are expected within four weeks, police said.
An anonymous tip-off led officers to the body by a road at Sutton Bank, near Thirsk, in 1981.
It is thought the woman may have died up to two years before her body was found.
Despite an 18-month investigation launched at the time of the discovery, and appeals for information since then, the identity of the woman remains unknown.
A wax impression of a woman's head was created using the body's skull to help identify the victim, but no information was received.
The woman was later buried in an unmarked grave in Malton. A North Yorkshire Police spokesman said the case was one of the force's "unsolved mysteries".
North Yorkshire Police said "significant advances" in DNA technology might bring them closer to identifying the body.
The force said it hoped to extract DNA from the teeth and femur of the body before reinterring it at Malton Cemetery on Wednesday.
Before the exhumation begins, a graveside blessing will be carried out by Force Chaplain, Reverend Simon Rudkin.
In a statement North Yorkshire Police said the exhumation was being carried out as the woman's family "deserve answers".
Malton Cemetery will be closed to the public throughout the operation. It is expected to reopen on Wednesday afternoon, police said.