A post mortem examination of a human head found in a quarry in Mepal on Monday (May 16) has come back inconclusive.
Specialists are still unable to identify whether the head belongs to a man or a woman, however, based on the information available at this time, it is believed the person died before January 1, 2015.
Detectives from the Beds, Cambs and Herts Major Crime Unit (MCU) continue to work with specialists in order to establish the gender and identity of the deceased.
Officers were called at about 3pm on Monday afternoon (May 16) after a worker at the quarry in Block Fen Drove made the discovery.
As part of the investigation, search officers have been carrying out activity at an aqueduct in Mill Road, Sharnbrook, Bedfordshire, as this is where the head is believed to have come from.
A police spokesman added: “No other body parts have been recovered.
“We are not linking this investigation to any others, however we are keeping an open mind.”
Scenes still remain in place at both the Mepal and Sharnbrook sites.
Anyone with information is asked to call the Major Crime Unit on 101 or Crimestoppers, anonymously, on 0800 555 111.