Carbon dating may be needed on the teeth of a skeleton found in Cork to determine the age of the woman and how long her body had been lying beside an old railway line.
The revelation came as gardaí are understood to be making "significant progress" with their investigation into the grim find at Roxborough, outside Midleton, last Tuesday.
Detectives believe they are dealing with the remains of a woman, who was possibly aged between 55 and 80 years.
It was initially suspected the remains were historic, dating back to the early 20th century and those of an adult male, possibly linked to the War of Independence.
The body is believed to have been at the site of the railway line for a number of years - but one source indicated the find is more recent than initially believed.
An examination of cloth and clothing found by the bones indicated that patterns could still be determined - suggesting that weather exposure had not totally destroyed or erased details.
DNA and dental records are now critical to helping solve the mystery.
However, carbon dating on the teeth could clarify the timeframe involved.
Gardaí believe the bones, some of which were found wrapped in cloth with a small piece of religious jewellery, are more recent than initially suspected.
Preliminary indications are that the remains do not fit the profile of any of Cork's major missing person cases.
The remains were found by workmen clearing part of the old Midleton-Youghal railway for conversion into a €19.8m greenway.
A workman operating a digger last Tuesday was shocked to see what he immediately feared was a human skull.
The area was sealed off and an examination of the site by gardaí yielded further bones.
The clothing fragments are also consistent with those normally used by an older woman.
The highest profile missing person case in Cork is Tina Satchwell from Youghal, who was 45-years-old when she vanished on March 20, 2017.
Searches off both the east Cork coast and in a Castlemartyr woodland failed to reveal any clue of her whereabouts.
However, preliminary indications are that the remains found in Midleton are those of a much older woman and that they have likely been in situ for longer than five years.
Gardaí believe the piece of religious jewellery could prove crucial in identifying the remains.