Grooming gangs that preyed on hundreds of girls and young women in the north east of England carried out their abuse with "arrogant persistence" as they did not fear investigation, a report has found.
The Serious Case Review, which was published to look into how authorities responded to child sexual exploitation (CSE) in Newcastle, found the perpetrators were "encouraged" to continue to abuse before a major operation was launched to stop them in 2014.
The report comes after a series of trials which saw 22 defendants sentenced for a range of offences including rape, drugs and prostitution.
The review estimated there were around 700 victims in total in the Northumbria Police force area, 108 of whom were from Newcastle.
The only abuser to help the inquiry was an asylum seeker who exploited a 15-year-old girl, who blamed his conviction on a "government conspiracy". The report said it was "unfortunate" there was not more input from other perpetrators.
Authorities in the region stepped up their response to CSE when they realised the problem was far worse than previously imagined.
Operation Sanctuary was launched by Northumbria Police in January 2014, a month after a young woman with learning difficulties told her social worker she had been sexually abused.
The Serious Case Review found the situation in Newcastle had improved since then and there was now no reluctance to start an investigation into grooming due to political correctness or fears of being branded racist - a factor in previous abuse scandals in other areas of the country.
But before 2014, the report stated that perpetrators were not consistently investigated and so went unpunished.
The report said: "This sent an unhelpful message to perpetrators - they were unlikely to be prosecuted or prevented from continuing to abuse - encouraging an arrogant persistence.
"It also had a significant impact on victims who learnt that nothing would be done against perpetrators."
According to the review, the abusers were mainly "not white but came from a diverse range of backgrounds including Pakistani, Bangladeshi, Indian, Iranian, Iraqi, Kurdish, Turkish, Albanian and Eastern European".
Barrister and CSE expert David Spicer who led the review, said other towns and cities could learn from Newcastle's response.
He said: "Unlike some other areas, Newcastle agencies did not try and sweep this under the carpet but actively went looking for it - and as a result, a large number of perpetrators were arrested and prosecuted, and victims saved from further trauma.
"That is not say that lessons have not been learned."
The review was carried out for Newcastle Safeguarding Children Board and Newcastle Safeguarding Adults Board.