The revelation that a section of Aidan McAnespie's rib cage, removed after he was shot dead 30 years ago, has been disposed of will be raised with the Northern Secretary, Tánaiste Simon Coveney has told the Dáil.

23-year old Aidan McAnespie was shot dead in February 1988 on the Tyrone-Monaghan border.

He had just walked through a British Army checkpoint at Aughnacloy, Co Tyrone on his way to Aghaloo GAA grounds to play a football match.

Documents that have emerged in recent days have revealed that the section of Mr McAnespie's rib cage that contained the exit wound from the shot that fatally wounded him was disposed of.

This afternoon in the Dáil, Sinn Fein TD Caoimhghín Ó Caoláin asked the Tánaiste to join him in "expressing alarm and exasperation" at the revelations contained in recent correspondence from the Northern Ireland's State Pathologist to the lawyers representing Mr McAnespie's family.

He explained: "The letter from Dr James Lyness advises that while the State pathologist's department has retained seven parafin tissue blocks containing wax embedded tissue from some of the major organs of Aidan's body. The section of the rib cage that contained the exit bullet had been disposed of."

He added, "Dr Lyness states that this disposal was carried out in the years following the post-mortem examination. But the state pathologist's department does not hold any records in relation to the disposal of retained tissue from that time."

"The rib cage section was removed from Aidan's chest cage adjacent to the breast bone. This rib cage section measured five inches by three inches. And was removed, I understand at the time of the autopsy carried out by the then deputy state pathologist in the North, Dr Carson."

"When Dr Harbison carried out the second autopsy on Aidan's exhumed remains here in this jurisdiction, he discovered that this critical section of Aidan's rib cage had been removed.

"There were many calls, historically and more recently, to have Aidan's full remains restored to his family but to no avail. Dr Harbison was unable to make a definitive judgement on the trajectory of the bullet that took Aidan's life."

The Cavan-Monaghan TD asked the Tánaiste to raise this matter with Northern Secretary Karen Bradley both in correspondence and face-to-face when they next meet.

He asked the Tánaiste to request that Ms Bradley will establish exactly when Mr McAnespie's removed rib cage section was disposed of.

He said that it is "bizarre" that no records were actually kept and it is "not credible".

Mr Ó Caoláin wants Ms Bradley to find out who carried out the disposal and under whose direction.

He also wants to establish if it is possible to retrieve the disposed remains and secure copies of all relevant documents including photographs of the rib cage section that the State Pathologist's office in Belfast holds.

Mr Coveney said the shooting was "a tragedy for his family and friends".

He has met the family and directed his officials to raise the matter with the Department of Justice in Northern Ireland.

He said that he is aware of the media coverage around the disposed body part.

He acknowledged that this is another "extremely difficult time for the family" who have been campaigning for the return of Mr McAnespie's remains in full.

The Tánaiste added: "this painful information must be all the more distressing by the long time the family have had to wait for it. We will try to establish the facts surrounding some of the issues that you have outlined and I will ensure that the issue is raised with the appropriate authorities."

Mr Ó Caoláin said the McAnespie family "believe that the rib cage section was removed in the first instance to cover up the fact that Aidan was hit by a single bullet fired from above and not from a ricochet off the roadway behind him. That view is now confirmed in the minds of many by the revelation that the critical evidence could attest to the trajectory of the bullet that is now no longer available to us."

The Tánaiste said he "cannot compel the State Pathologist in Northern Ireland to provide information but I can certainly raise concerns with the Secretary of State. I can understand why you are asking the questions you are asking."

He added: "we are trying to move ahead with a comprehensive and structured response to try to deal with legacy."

He said there are many families in Northern Ireland from both communities that are trying to deal with very painful memories of murders and atrocities in Northern Ireland.

"I certainly hope the McAnespie family can also establish in time the full truth in relation to what happened to their son," Mr Coveney said.