Operation Span was hailed as "a fantastic result for British justice".
On the face of it, it was a success; in 2010 an investigative team had turned things around after a failed investigation into a grooming gang in the south of Manchester, Operation Augusta, and by May 2012 with renewed vigour had convicted nine men for serious sexual offences against children in the Rochdale area.
And yet almost immediately there were serious questions about whether this new Greater Manchester Police (GMP) investigation had also fallen short.
Six months after the convictions, a detective who had worked on Operation Span, Maggie Oliver, resigned and turned whistleblower.
She claimed the investigation was curtailed; allegations by key witnesses were not investigated, and numerous more abusers remained at large. She said some alleged abusers hadn't even been questioned by the police.
One victim - known as Amber - said 20 to 30 men abused her and was able to positively identify eight out of 10 of her abusers in the first of three planned identification parades.
Ms Oliver claimed that the police were reluctant to extend the investigation and thus none of Amber's interviews were put on the system, no crimes were recorded, and nothing was recorded in respect of the suspects.
In the end, prosecutors made a tactical decision to name the victim on the indictment as a 'co-conspirator,' to ensure her evidence was heard by the jury.
Today's review describes that decision as "deplorable".
The six-year investigation into Operation Span, commissioned by Manchester Mayor Andy Burnham is, in the mayor's own words, "a hard read".
It reviewed the cases of 111 children on police files during the period of Operation Span, and found that there was evidence that 74 of them were being sexually exploited and, in 48 cases, there were "serious failures to protect the child".
'Children were left at risk'
Despite the nine convictions, lessons had not been learned from the failed Operation Augusta.
The report found: "Child Sexual Exploitation (CSE) continued to be low priority and under-resourced by GMP."
Added to this, authorities turned on the whistleblowers.
Two serious case overview reports, published by Rochdale Local Safeguarding Children's Board in 2013, criticised sexual health worker Sara Rowbotham who had helped expose the child abuse ring.
It was claimed her Crisis Intervention Team had not communicated properly with the relevant authorities.
Today's report contradicts that, saying she was "unfairly criticised" and that there was compelling evidence police were aware her team had shared explicit information, telling children's social care about 127 potential victims - but this information "had not been acted on over the years".
The report's lead author, Malcolm Newsam, concludes: "Children were left at risk and many of their abusers to this day have not been apprehended."
Responding to the findings, Greater Manchester Police's chief constable, Stephen Watson, said the report "reinforces the importance of the changes we have already made - many with Maggie's support," and goes on to say that responses have been "overhauled since the early 2000s to ensure that victims and survivors are cared for and receive the expected level of service".
Victims 'still routinely treated badly'
At the time of writing, it hasn't happened yet - but expect, in a press conference today, Maggie Oliver to strongly reject both the idea that she has been involved in change - and that anything has changed.
In a statement released before the press conference, she said: "I can absolutely, categorically say that through our work today at The Maggie Oliver Foundation, we see on a daily basis that victims and survivors of sexual offences are still routinely treated badly or even inhumanely, still not believed, still judged, still dismissed when they report these horrendous crimes."
She added: "Just ask any of the 4,000 plus victims we have fought alongside over the past five years. We see lines of investigation not followed and have to advocate relentlessly for those desperate survivors seeking our help."
Only last year Sky News reported on the case of a young woman, Scarlett, now 19, who waived her anonymity to tell how she felt failed by the police after being groomed from the age of 14 and sexually assaulted.
Her father Marlon told Sky News he was shouted at by the police missing persons team and told to stop reporting his daughter missing.
Also last year, following a Sky News Investigation, Mr Burnham commissioned the Baird Inquiry into GMP's treatment of women in custody and use of strip searches.
Scarlett was one of the subjects of the review, having been strip-searched at the age of 14.
Another woman, who claimed to have been unnecessarily strip-searched in a police cell, had previously made complaints against the police about failures to pursue an alleged child sexual abuse case.
Complaints procedure 'utterly unfit for purpose'
Ms Oliver says: "In the worst of cases, we see those who dare to complain about their investigations or treatment by police forces subjected to police intimidation, false arrests or often being themselves criminalised."
She adds: "We have seen that the police complaints procedure is totally and utterly unfit for purpose."
She says complainants are under the false impression that their cases will be dealt with by the Independent Office for Police Conduct (IOPC), adding: "What actually happens though is that these complaints to the IOPC are forwarded directly to the force in question to 'mark their own homework'."
However, GMP claims there have been vast improvements in the decade since Operation Span concluded.
The force's Child Sexual Exploitation Major Investigation Team now employs 120 police officers and staff. Since the nine men were convicted in 2012, there have been a further 135 arrests and 32 convictions.
According to Rochdale Council, recent Ofsted inspections have found "the way children at risk of sexual exploitation are protected by Rochdale's children's services has improved".
However, in February 2022, Ofsted found a children's home run by the council failed to protect youngsters at risk of sexual exploitation or "effectively monitor" their whereabouts - rating the home as "inadequate".
Rochdale now has a 'Complex Safeguarding Hub' - also known as The Sunrise Team - which focuses on the safeguarding of vulnerable young people.
The team runs proactive operations - for example, under Operation Cobalt, they visit hotels and taxi companies to educate staff on the signs of child sexual exploitation and how to report concerns.
And Operation Vigilant was set up to gather intelligence from within communities.
The mayor's office says that in 2023, the team also conducted seven days of action and seized over 4,700 illegal vapes - which intelligence suggests are sometimes being used to groom vulnerable young people.
Police 'do not understand'
Rochdale Council leader Councillor Neil Emmott said: "Every Ofsted inspection since 2014 has concluded that Rochdale responds to reports of child sexual exploitation effectively through our dedicated multi-agency Sunrise Team.
"We have offered and continue to offer support to those survivors of child sexual exploitation in Rochdale."
But more widely there are still questions over whether police forces understand the complexities of grooming cases - only last month, in a study of several unnamed forces, the police regulator said it was "disappointed" to discover that police do not accurately understand the issue and that, "most forces weren't gathering data and intelligence on these crimes".
The review published today into Operation Span is the third of four reviews commissioned on this subject.
The last one, which begins now, will focus on current practice in dealing with Child Sexual Exploitation by GMP.
That's due to report back in the summer.