DNA AND other tests are being carried out on an incomplete set of human remains discovered on a Wicklow hillside.
The discovery is being linked with the abduction, murder and secret burial in 1981 of a young west Belfast man.
The IRA admitted in a statement in 1999 that 18 years earlier it had taken and questioned Daniel McIlhone, who is now referred to as one of the so-called "disappeared".
A spokesman for the Independent Commission on the Location of Victims Remains, the cross-Border body tasked with finding the disappeared, said last night: "Partial human remains have been recovered by a team working on behalf of the independent commission . . . which is currently ongoing at the site in Co Wicklow."
The Irish Times was told that a search party working for the commission made the discovery on Saturday in the Ballynultagh area of the county. However, it was not immediately obvious if the find comprised human remains.
A series of digs have been carried out for more than two years as part of the search for Mr McIlhone. Two unsuccessful searches in the general area have already been made.
A review of the searches was ordered by the Irish and British governments in 2005 and the specialist services of a forensic expert were called in.
The McIlhone family have been informed of the discovery despite the lack of firm identification. It is understood their co-operation could be needed to help establish if the remains are indeed those of the missing man.
It is possible that the human remains are not those of Mr McIlhone but this is thought unlikely at this stage, a reliable source said last night.
DNA tests could take anything up to six weeks to provide conclusive identification. Other attempts at identifying the remains were also being made.
The IRA statement released in 1999 does not refer to Mr McIlhone as an informer. However, it does say he was taken for questioning by its members over a case of alleged arms theft.
It was also claimed that he died in a struggle with the person or persons holding him.
The commission tasked with locating the remains of the nine disappeared was established in 1999 in the wake of the Belfast Agreement as part of an effort to provide "closure" to their families.
Four bodies have been discovered and returned to their families for burial. On the date that the establishment of the commission was formally announced, the body of Éamon Molloy was left in a graveyard in Co Louth.
The remains of Brian McKinney and John McClory were also unearthed following a series of digs at a site in Co Monaghan.
In 2003, the remains of mother of 10 Jean McConville were found on a beach in Co Louth. Information provided by the IRA has been used to make the discoveries to date.
Last week Sinn Féin president Gerry Adams told the Assembly that republicans who had been involved in the conflict had already passed on information about the disappeared to the commission.
"I want to acknowledge once again the grave injustice inflicted on these families and to express my deep regret about this," he said.