Social services and police "missed opportunities" to stop the sexual abuse of young girls in Rochdale, a report into a grooming scandal has revealed.
"Deficiencies" and "patchy" training of front-line staff were behind the failings, the Rochdale Borough Safeguarding Children Board said in its review of child sexual exploitation.
It comes after nine men were jailed in May for grooming girls as young as 13.
Lawyers say the findings could support "legal action against social services".
The report - ordered after the grooming cases came to light in Rochdale, Greater Manchester - reviews the work of local agencies, including the council, police and the Crown Prosecution Service between 2007 and 2012 in safeguarding children at risk of sexual exploitation.
Using feedback from 23 support staff, it charts the experience of one victim from 2007 to 2010.
It reveals the girl spoke to support workers on several occasions about being abused - including giving a detailed complaint to detectives.
However, the report suggests some child protection services failed to act and the abuse continued.
It says: "While some organisations were consistently supportive in their response, overall child welfare organisations missed opportunities to provide a comprehensive, co-ordinated and timely response and, in addition, the criminal justice system missed opportunities to bring the perpetrators to justice."
It also reports that "activity to disrupt alleged offenders was developing on the ground, but this was not always followed through at a more senior level".
"The early investigations of crimes and the prosecution of alleged offenders were flawed."
The report also shows some officials believed vulnerable girls as young as 10 - who were being groomed for sexual abuse - were "making their own choices".
One of the girl's parents said they were simply told their teenage daughter was hanging out with a bad crowd, it says.
Welcoming the report, a father of one victim said he wanted "to see people named, shamed and sacked".
"I don't want them transferred to another department, pensioned off or given early retirement."
He added: "I do spot that there's no reference to the question of race in the report, as to whether that was a factor in their lack of willingness to act."
During the trial there were demonstrations by far-right groups after it emerged that white girls were being exploited by the gang, eight of whom were of Pakistani origin, with another from Afghanistan.
Greater Manchester Police said that there was no racial element to the case, and that the main issue was older men exploiting vulnerable young women and girls.
However, following the gang's convictions, Labour MP for Rochdale Simon Danczuk said it would be "daft not to believe that race plays a part" in the grooming.
Mr Danczuk, who described the report as "limited", said it did not "give a voice to the victims [or] explain why social services had a culture of blaming the victims for the abuse".
Richard Scorer of Pannone Solicitors, which represents one of the victims in the recent case, said he expected legal proceedings to follow, as the report gave a "pretty firm basis for legal action against social services".
He said there was "clear evidence that social services failed to intervene when they had information about grooming and exploitation of young girls".
Lynne Jones, chair of the Rochdale Borough Safeguarding Children Board, said the council had "responded" to the review and had "improvements" had already been put in place.
"I believe organisations are working better together, sharing information to ensure children are protected and that perpetrators are prosecuted," she said.
She added that literature aimed at "raising awareness" of abuse had been given to 10,000 young people.
In May, nine men who ran a child sexual exploitation ring in Rochdale were jailed at Liverpool Crown Court after being found guilty of offences including rape and conspiracy to engage in sexual activity with girls under the age of 16.
The court heard the group plied five victims with drink and drugs and "passed them around" for sex.