The IRA has insisted murder victim Jean McConville was working as an informer for the British army.
A widowed mother of 10 children, Mrs McConville was abducted and killed in December 1972 by the IRA, which later claimed she was passing information about IRA activities at Divis Flats in West Belfast.
The North's Police Ombudsman Nuala O'Loan yesterday concluded that this was incorrect and cleared Mrs McConville of the allegations.
However, in a statement released today, the IRA said: "Following a public request from the family of Jean McConville the IRA carried out a thorough investigation of all the circumstances surrounding her death.
"That investigation has confirmed that Jean McConville was working as an informer for the British army.
"The conclusion of this investigation was reported to Michael McConville.
"The IRA accepts that he rejects this conclusion.
"The IRA regrets the suffering of all the famillies whose loved ones were killed and buried by the IRA."
Mrs McConville's body was found 31 years after her killing when walkers stumbled upon it on a beach in Co Louth in August 2003.
It was 27 years after her abduction before any information was available on her fate. Finally, in March 1999, the IRA confirmed it had carried out the killing but alleged she was an "informer" who admitted passing information to the British army.
Michael McConville welcomed the clearing of his mother's name yesterday: "The stigma of it has always been very hard to bear. What people keep saying is that she was an informer. We as a family know fine rightly that my mother was never an informer."
SDLP leader Mark Durkan accused the IRA of issuing a negative and self-serving statement.
"It is deeply regrettable that the McConville family continues to be denied justice for their mother's memory.
"I hope the McConville family can take comfort from the fact that decent people fully accept the verdict from the Police Ombudsman and are likely to be cynical about another self-serving version of events from the IRA."