The investigating officer in the original Kingsmills massacre investigation has confirmed that crucial forensic evidence in the case was lost.
DCI James Mitchell told the inquest today that paint, glass, soil and metal from the scene of the 1976 murder of ten Protestants in South Armagh was taken by forensic officers.
The suspected getaway minibus was also examined by NI forensic officers in Dublin where a palm print of a suspected gunman was also found.
The aim had been to match samples from the van to samples at the crime scene.
However some of the scene of crimes samples were destroyed at a fire eight months later in Northern Ireland and others were later destroyed, the inquest heard today.
Mr Mitchell said this evidence could have placed the getaway minibus at the scene.
A match was made with the palm print and a south Armagh suspect in June last year and the inquest was stopped while efforts were made to prosecute him.
However the PPS dropped the case because it said it could not prove the getaway minibus had been at the scene of the massacre.
Mr Mitchell said the lost evidence was potentially very important but that police had followed all procedures properly relating to it.
He could not show any evidence that police had chased forensic officers for the results of the tests.
He also apologised to families in court for weaknesses and gaps in the investigation which he said were in large part down to major staff shortages at the time.