Gardai are now satisfied that the human skull found during excavation work on land near a housing estate was there less than five years.
Special digging equipment will be brought in by officers today as they extend the search of the land at Waterside, near Malahide, in north county Dublin.
Gardai are hoping that further body parts will be uncovered during the extended search and think that some may have been disturbed over the past few years.
A preliminary examination of the skull by State pathologist, Professor Marie Cassidy, found no indication of serious injury.
However, more detailed tests on the skull will get under way today, while attempts will also be made to compare DNA records with those on garda missing persons' files in the area.
Gardai said it was too early to speculate on an identity.
The site search is expected to last several days and is expected to be visited by State anthropologist, Dr Laureen Buckley.
The find was made by workmen clearing a ditch on the land on Wednesday afternoon. The area has been sealed off by gardai since then.
Officers said it could take several days before it is firmly established how long the skull had lain on the land, but they are satisfied it was five years at most.