A skull found by workmen clearing a drain will be forensically examined by experts tomorrow to determine its age.
The skull was discovered during excavation work on land at Waterside, near Malahide, in north county Dublin.
Gardai were contacted this evening following the discovery and sealed off the area - a field located near a housing estate - which is close to the M1 motorway.
Officers preserved the scene overnight after carrying out initial inquiries with the help of lighting equipment.
They contacted the office of the State Pathologist, Professor Marie Cassidy and a detailed examination of the skull will be carried out tomorrow by forensic anthropologist, Dr Laureen Buckley.
A senior garda officer said tonight that this should determine whether the find is historical or is more recent.
He said gardai were awaiting the outcome of the tests before deciding on further inquiries.
Earlier a JCB digger was being used to turn the soil in the field in preparation for ploughing.
"The field is going to be used for growing vegetables or potatoes. It's privately owned as far as I know,"a local resident explained.
"A search spotlight also later appeared in the area," he added
"Obviously they came across something they weren't expecting. The gardai arrived at around 7pm and that's when I noticed the giant spotlight."
"There's a laneway down to the field and children would play in that area quite a lot."
A garda spokesman said early indications suggest the remains are human.
“It could be historical or otherwise - but we are not sure at this stage," he added.
“The scene will be preserved overnight ahead of an examination tomorrow.”