Three girls at the centre of the collapsed Western Isles child abuse case had been sexually assaulted, an inquiry has revealed.
Social work inspectors said those dealing with the case lacked expertise and that the children should have been removed from their home much earlier.
Nine people were charged following a series of dawn raids in 2003 but the accusations were dropped last year.
The Crown Office decision followed examination of the available evidence.
Western Isles Council (Comhairle nan Eilean Siar) asked the Social Work Inspection Agency (SWIA) to look at the way the case was handled following its collapse in 2004.
Publishing its findings on Friday, the agency said the three girls - who have been given the names Alice, Barbara and Caitlin in the 170-page report - were neglected and abused over many years.
The children's mother had been abused by her own father, according to the report. She married a man who had a previous conviction for indecently assaulting his child.
When the allegations by the three girls first emerged, they and their mother were interviewed by social workers and the police.
The girls, who now live with foster parents, asked for the report to be published in full so that their story could be told.
Nine people, including a 75-year-old woman, were arrested in a co-ordinated series of raids on Lewis and in England in 2003. They were charged with offences including rape.
In July 2004, the Crown Office announced that all charges had been dropped.
The agency report said social workers and managers should have acted sooner to protect the children.
More than 220 indicators of sexual, physical and emotional abuse and neglect were found. The latter involved one child having to eat cat food and another slept in a cupboard.
Health professionals failed to respond appropriately and the isles' NHS board did not have systems in place to help protect the children.
A social worker decided to reclassify the main suspect as "low risk" because records were not passed on by social services in England.
Alexis Jay, the agency's chief inspector, said her team found the girls' parents had "consistently failed" to care for or protect them.
She told a news conference: "We found evidence of physical abuse, emotional abuse and neglect as well as symptoms and behaviour which strongly suggested sexual abuse.
"We believe that all these three children were repeatedly sexually abused."
Alexis Jay reads from a statement at the news conference
"Our conclusions are based on a range of evidence from records going back to 1989, witness statements from professionals who knew the children at different periods in their lives and also from the children's own statements."
She said the agency also concluded that the children were physically abused throughout their lives "by a number of adults".
The report does not explain why the case was dropped. Ms Jay said that was not its remit.
It makes 31 recommendations, 10 of which relate to the Scottish Executive.
Education Minister Peter Peacock has issued an ultimatum to agencies involved with child care in the Western Isles, giving them until 30 November to "sort out weaknesses in inter-agency practice".
He said: "This report writes yet another horrifying chapter in the continuing exposure of child abuse in Scotland.
"In this case the professional agencies involved knew of, and recorded, extensive concerns about the girls' welfare and well-being over a number of years but inspectors found they didn't intervene early enough."
Mr Peacock said he had asked the inspectors to work closely with the agencies involved and ensure that lessons were learned "throughout Scotland".
Bill Howat, chief executive of Western Isles Council (Comhairle nan Eilean Siar) said:" We accept that there were serious shortcomings in our performance in the case and that is a matter of regret."
Northern Constabulary welcomed the findings and stressed that the force had correctly followed all available guidance.
Chief Constable Ian Latimer said: "We had a sufficiency of evidence to charge a number of people and we did.
"As in all serious cases, the decision as to whether a criminal prosecution should be undertaken is a matter for Crown Counsel alone.
"Despite the fact that the accused persons did not face a criminal trial, I am confident that the police investigation was of a high standard."