The IRA's decision to insist that Belfast woman, Jean McConville was an informer 30 years after it killed her has surprised the Government, Taoiseach Bertie Ahern has said.
"I really don't know that, and neither does any of our people. We have no information on it," said Mr Ahern, following the IRA's public disagreement with Northern Ireland Police Ombudsman Nuala O'Loan.
Following an inquiry, Mrs O'Loan, who spoke with the Police Service of Northern Ireland, the British Army and the British security services, said she was certain that the mother had never been a British informer.
The brutal murder of the woman, who was secretly buried and whose body was not found for nearly 30 years, has proven to a major embarrassment to the Provisional IRA.
Ulster Unionist Party leader Sir Reg Empey accused the IRA of trying to rewrite history.
He said the organisation was "scraping the bottom of the barrel" in its statement insisting Mrs McConville was an informer.
"There has been a lot of comment over the weekend focused on the fact that Mrs McConville was not an informer, while the IRA claimed she was.
"What has been overlooked is the fact that Mrs McConville should not have been murdered and the IRA's 'justification' should not be the main issue," he said.
"One can only guess at the distress all this is causing to the family.
"But the issue illustrates that families up and down the land will be subjected to the same sort of stress for many years to come as the IRA attempts to rewrite history," added Sir Reg.