A whistleblower has claimed senior police "betrayed the public" and tried to "bury the truth" after a report said police"failed" child sex abuse victims.
Former detective Maggie Oliver, who resigned from her job over the scandal, said the report "makes me want to sing from the rooftops" as Greater Manchester Police (GMP) issued a public apology.
The force have also referred themselves to watchdog the Independent Office for Police Conduct (IOPC) and relaunched a criminal investigation with 38 potential victims identified so far.
The report was ordered by Andy Burnham, Mayor of Greater Manchester, after BBC documentary The Betrayed Girls, which aired in 2017, featured Ms Oliver - who he said had been "fully vindicated".
It centres on Operation Augusta, set up in 2004, which was prompted by the death of Victoria Agoglia, 15, a girl under the care of Manchester City Council, who reported being raped and injected with heroin by a 50-year-old Asian man.
She died of a drugs overdose two months later on September 29, 2003.
The police operation launched in response the year after identified at least 57 victims and 97 potential suspects, some involved with Ms Agoglia, and a "compelling picture of the systemic exploitation of looked after children in the care system" was established by detectives.
But senior officers at GMP chose to under-resource the investigation, the report said, and a decision was made to close it down in 2005.
Joan Agoglia, Victoria's grandmother, broke down in tears at a press conference in Manchester with Mr Burnham, Ms Oliver, and the report's authors.
Mrs Agoglia said her granddaughter went into care against her wishes after her own daughter developed terminal brain cancer.
She added: "She was such a lovely girl, a wonderful girl. She didn't deserve to die. I've been fighting all my life for this. She told me herself what these men had done to her.
"I used to give her a bath because she was so bruised. I promised her...there's no way they are going to get away with this."
Ms Oliver said when she raised concerns, she was met with "misogyny" and the "old boys' network", described as an "emotional woman" and dismissed as "too involved" with victims.
She said: "The question I would ask everyone to consider today is, what is the real cost of all these lies?
"Fifteen years the perpetrators we knew on Operation Augusta were abusing generations of children, and were allowed to walk free.
"Those children were just cast to the wind.
"I'm talking about people at the top of the police and at the social services.
"The people who knew the facts, knew the truth and they chose to bury the truth.
"That, in my opinion, is unforgivable.
"The question I would raise is, 'Why are these people not facing charges of misconduct in a public office?'
"Where is the accountability?"
No one has been disciplined or reprimanded from the police or social services, and most of those involved are understood to have retired.
Mr Burnham said disciplinary action was a matter for the chief constable of GMP, and while Operation Augusta was closed down under a previous chief constable, the report did not uncover evidence it was "wilfully obstructed" or "unethically stopped."
He added: "The report makes extremely difficult reading. Victoria's death should have been a wake-up call on child sexual exploitation to the whole of Greater Manchester.
"But it wasn't. Her death exposed a network of paedophiles brazenly abusing young people - girls and boys - in care.
"Each and every one of those abusers should have been brought to justice but, appallingly, most escaped and some were left to reoffend."