The search will resume this morning for the remains of Mrs Jean McConville, who is thought to be buried under the carpark at Templeton beach, near Carlingford, Co Louth.
According to Chief Supt Michael Finnegan, who is heading the operation, a specific parking bay was identified as Mrs McConville's burial place to the Independent Commission for the Return of Victims' Remains. The commission was told she was buried between three and five feet under the surface.
However, the carpark was built on the sand dunes 12 years ago - 14 years after the murder.
"We're working on the assumption the bodies are where we were told", Chief Supt Finnegan said. "But you're talking about shifting terrain." He said aerial photographs and videos of the beach were taken yesterday to help pinpoint the location of the grave.
The surface of the parking bay, an area about 12 by six feet, was removed on Saturday night, and digging began at 7.30 a.m. yesterday.
Gardai in pale blue overalls dug under the direction of Insp Gerry Smith, and the earth was removed by wheelbarrow. By 1 p.m., they had dug to 6ft without finding anything and they decided to bring in a mechanical digger. This arrived shortly after 4 p.m., and it was used to remove the tarmac surface of a further 6ft on either side of the existing crater.
The gardai then returned to patient manual digging, examining each shovelful before placing it in the bucket of the mechanical digger which deposited it at the side of the carpark.
According to local gardai, the beach is a favourite spot for courting couples. On a normal summer day the carpark would be full as families played on the beach, but yesterday the cold wind kept people away.