The IRA statement follows an assertion on Friday by the police ombudsman, Nuala O'Loan, that her office had found no evidence McConville was ever an informer. O'Loan was speaking after her officers carried out an extensive investigation into the claims.

McConville, 37, was abducted, murdered and secretly buried in 1972. Republican sources have always insisted she was an agent. In its statement, the IRA said it had conducted its own "thorough investigation" which confirmed McConville "was working as an informer for the British army". The IRA said its inquiry followed a "public request" from the McConville family and that its conclusion had been reported to her son, Michael. "The IRA accepts that he rejects this conclusion, " the statement said.

"The IRA regrets the suffering of all the families whose loved ones were killed and buried by the IRA, " it added.

For years, the IRA publicly denied having abducted, murdered and secretly buried McConville.

But in 1999, the Provisionals admitted they had killed the mother of 10 and several other of the "disappeared".

McConville, a widow, was abducted shortly after she went to the aid of a fatally wounded British soldier outside her home in west Belfast.

Her remains were finally found at Shelling Hill beach, Co Louth, in August 2003.