A proper investigation into the IRA's killing of Jean McConville was not carried out for more than 20 years, the NI police ombudsman has said.
Jean McConville was abducted and murdered in 1972
Nuala O'Loan said there had been intelligence that she was still alive some time after being abducted from her home in December 1972.
Her inquiry found there was no formal police record of her disappearance, nor of attempts at the time to find her.
Mrs O'Loan upheld a complaint brought by two of Mrs McConville's children.
The investigation of her murder will now form part of the work of the PSNI Historical Enquiry Team.
Mrs McConville, who was a widow, was killed after she went to the aid of a fatally wounded British soldier outside her home in west Belfast's Divis flats.
The IRA insists the mother-of-10 was a British army informer, although a police ombudsman inquiry earlier this year found no evidence of this.
Mrs McConville's remains were finally found at Shelling Hill beach in County Louth in the Irish Republic in August 2003.
Mrs O'Loan said: "By 16 January (1973) a spokesman was being quoted as saying the matter was being investigated but we have found no evidence of this.
"There is no crime file about any investigation of the abduction in 1972.
"Even if we look at the intelligence the police received which suggested that Mrs McConville was alive and had either left of her own will or was being held by the Provisionals in Dundalk, we found no evidence that either of these issues were looked at.
"An Garda Siochana (Irish police) have said they are not aware of an investigation by them into Mrs McConville's death prior to the discovery of her body."
Mrs McConville's son Michael said he felt vindicated by the report.
"They didn't do enough work on the case in the first place, I think it was a big let down for the McConville family," he said.
"If police had reacted more quickly, my mother might have still been alive today. I think that to start an investigation 20 years later is a bit late."