Forensic tests are to be carried out on a human skull found on a beach in Barra.
A spokesman for Northern Constabulary said the skull was found by a member of the public at around 5pm on Saturday at the Western Isles beach.
Tests will be carried out to determine the age of the skull and where it has come from.
The spokesman added: "At this time, there is little information in order to progress any form of identification and the remains are subject to numerous forensic investigations to establish any time frame for them.
"There is no information to indicate this to be as a result of any recent death and no other bones or remains have been found."
Anyone with information is asked to contact Northern Constabulary on 01851 702222 or confidentially through Crimestoppers on 0800 555 111.