Grooming gangs that preyed on 700 vulnerable girls and women in and around Newcastle developed an "arrogant persistence" because the authorities locked up the victims rather than the offenders, a Serious Case Review has found.

Operation Sanctuary, which was launched in 2014, resulted in 112 offenders being jailed for a total of almost 500 years for abuse carried out against more than 270 victims.

But a shocking report has revealed that the actual number of those targeted was at least 700, as gangs of men from a range of backgrounds plied victims with drugs before raping and forcing them into prostitution.

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".

In some cases the victims of the gangs were placed in secure accommodation because of what was seen as their poor behaviour, while the offenders were seen to be innocent and went unpunished.

Efforts to find out why the perpetrators thought they could abuse vulnerable women and girls have been rebuffed, with only one defendant agreeing to help the inquiry, and he denied guilt, blaming a government cover up.