South Yorkshire Police 'still letting down' abused children
Update 17 March 2016: After this article had been published, South Yorkshire Police issued a correction to its figures and said those supplied to the BBC had been wrong. Instead of charging one person for every 16 CSE complaints, it said the figure was one for every 3.4 complaints, compared with an average across nine other forces of one in five. We have published a separate story that explains the background and reaction to this.
The police force at the centre of the Rotherham abuse scandal has been dubbed "substandard" on tackling offenders.
South Yorkshire Police has charged one person for every 16 child sexual exploitation complaints over two years.
It also brought among the fewest prosecutions of child abusers in the past three years, according to the CPS.
Lib Dem Lord Scriven said victims had been "let down", while the force stressed CSE investigations involved "highly complex evidence".
Former children's minister Tim Loughton said charges and prosecutions by South Yorkshire were "completely out of sync" with other forces.
South Yorkshire was among 10 constabularies to which the BBC sent Freedom of Information requests.
The average charging rate across the other nine forces was more like one charge for every five CSE complaints; with the figure at one in eight in the West Midlands, Hampshire and Leicestershire.
The CPS provided separate figures for prosecutions for child abuse - including sex crimes, child prostitution, child cruelty, trafficked children and historical abuse where the victim was now an adult.
It comes as survivors are due to share their personal experiences at a conference on CSE on Friday, to learn lessons from the Rotherham abuse scandal.
On Wednesday, the NSPCC said the number of reported child sex offences had risen by a third in England and Wales in a year to the equivalent of more than 113 a day.
Asked what he believed the BBC's research showed, Lord Scriven said it highlighted how South Yorkshire's Chief Constable David Crompton had failed to act with the "speed and severity required" to stop childhoods "being ruined by abuse".
The peer's comments came despite recent jail terms for three brothers who led a grooming gang a judge said caused harm of "unimaginable proportions".
Repeating his call for the chief constable to resign, Lord Scriven said: "We need to solve this for the sake of confidence in the police and the victims.
"I feel the chief constable is not the man to take this force forward."
The Conservative MP Mr Loughton said: "I will be raising these figures with the Home Affairs Select Committee."
South Yorkshire Police said the nature of CSE investigations might mean it took longer than a year to prosecute offenders and some may be charged with multiple offences.
"In the last month five people have been jailed for a total of a 102 years for a number of CSE-related offences in Rotherham. This demonstrates the determination we have to bringing those responsible for this type of crime to justice," said a spokesperson.
South Yorkshire is not alone in receiving criticism for not tackling child sex abuse: Thames Valley Police and Oxfordshire County Council were found in a serious case review in March 2015 to have made "many errors" and there was condemnation for authorities after the Rochdale grooming case.
The scale of the problem identified in Rotherham, however, dwarfed other towns and police watchdog Her Majesty's Inspectorate of Constabulary found in July the force still needed to make "major improvements" to some child protection procedures.
Retired Det Ch Insp Simon Morton, who led the Thames Valley Police investigation into abuse in Oxfordshire uncovered during an inquiry dubbed Operation Bullfinch, said he thought the number of charges across the 10 forces was "promising" because of the difficulty and distress for victims in building evidence to bring cases to court.
Stockport's Labour MP Ann Coffey, who authored a report in the wake of the Rochdale grooming case in 2012, said the number of reports suggested greater awareness among police of CSE but she was "not convinced" of greater public awareness.
"Until that happens, I don't think we will have a high level of prosecutions as members of the public make up juries."
In law, there is no specific crime of child sexual exploitation. Offenders are often charged for associated offences such as sexual activity with a child, but police forces record these associated crimes internally with CSE flags or markers, meaning they have safeguarding concerns about a child. The BBC requested numbers of offences with a CSE flag.
The 10 forces started highlighting CSE separately over the past four years - with Greater Manchester the first in July 2012 and Durham the last in November 2014 - but in that time there have been thousands of reports including from children's homes, schools and hotels.
Peter Garsden, from the Association of Child Abuse Lawyers, said "wide discrepancies between recording efficiencies in different [police force] areas" could affect investigations, with knock-on effects for victims.
Such was the demand, Barnardo's launched a fundraising appeal for £500,000 to keep its existing, voluntary-funded CSE services open "with the ambition to open more".
Javed Khan, Barnardo's chief executive, said more victims came forward "every time" it opened a new service.
"Sadly, we then have to prioritise the most high-risk cases as our services are usually oversubscribed," he said.
Many of the reports have been made since the full extent of the Rotherham scandal was revealed in the Jay report, in August 2014.
Insp Julie Woods, from West Midlands Police's public protection unit, said more children were reporting abuse.
She said: "However, children are often very reluctant to talk and where there is evidence to support a criminal justice route we will always proceed with a victimless prosecution, obviously with the support of CPS."
Durham Constabulary CSE specialist Helen Murphy said social media was used by offenders to meet children and "play on their innocence and naivety".
The "vast majority" of sexual abuse of children was however committed in their homes "by people who should be protecting them", Ms Murphy added.
Hampshire Det Supt Victoria Dennis said: "Victims of CSE can take many months, sometimes years, to be able to disclose what has happened to them. This can result in the investigation not progressing to a charge or prosecution if there is insufficient evidence at that time.
"The force is not struggling to investigate these offences; we have adequate resources to investigate these offences thoroughly."
Leicestershire Police said it had launched a new campaign called CEASE - the Commitment to Eradicate Abuse and Sexual Exploitation in Leicester, Leicestershire and Rutland.
Dorset Police said it gathered evidence towards prosecutions even without complaints from victims and "regardless of the outcome...continued to support victims and help them minimise any risks to which they may be exposed".
Staffordshire Police said figures showed offences and the number of people charged over a specific time period highlighted CSE offenders were often charged with more than one offence, "which may mean that the proportion of people arrested per offence differed".
The force said it had teams to target CSE on the street, online and a multi-agency prevention team, which meant it "uncovered a greater number of offences" due to its "active focus".