Arshid Hussain was jailed for 35 years in 2016 for 23 offences against nine girls after being revealed as the ringleader of a child grooming gang in Rotherham.
Now, an investigation into police misconduct in the Rotherham child abuse scandal has upheld a complaint that validates a "no arrest deal" allegation.
It finds that South Yorkshire Police did not respond appropriately to the incident with a 14-year-old pregnant girl in 2000.
A previous South Yorkshire Police investigation, in 2013, found "no evidence to substantiate" the no arrest claim after it was first reported.
But Hussain was found guilty of abduction in 2016, after a jury heard evidence that a now-deceased police officer called Hassan Ali had been involved in arranging for Hussain to hand over the girl in exchange for him not being prosecuted.
Hussain will be in prison for at least 35 years Danny Lawson
The Independent Office for Police Conduct (IOPC) has now upheld a complaint about the police handling of the incident.
And South Yorkshire Police has fully accepted the findings, which examined allegations of police misconduct during the Rotherham abuse scandal.
The IOPC ruling reads: "We upheld the survivor's report that SYP did not respond appropriately in a child abduction case which ended with the survivor being handed over to officers by the CSA/E perpetrator as part of a 'deal' not to arrest him.
"We found no evidence the police ever issued the perpetrator with a child abduction warning notice, or harbouring notice.
"We found SYP knew the perpetrator's name and address and the incident happened with the knowledge that the survivor had been found with the perpetrator on several occasions in the past. "We identified that the incident was not fully recorded by the force or added to its intelligence system nor shared with other agencies.
"The survivor reported that SYP's dealings with them were not in line with appropriate policy and guidelines. We upheld this complaint, noting especially a general failure by SYP to properly record information about the CSA/E risk to the survivor."
Records from a Family Crisis Response Team worker on the day of the alleged handover said they had "got" the victim" after a community policeman "did a deal" and arranged to meet at a "neutral venue" – believed to be a petrol station.
The court was told PC Ali had denied the incident had ever happened.
PC Ali died in 2015 following a fatal collision with a car on the same day that he had been informed he was being placed on restricted duties in relation to complaints that had been made against him.
A man was subsequently found not guilty of causing death by careless driving in relation to the incident.
The IOPC's report does not go into further detail about the case or name the officer or offender involved.
But The Yorkshire Post reports that the details of the ruling relate to the incident.
A total of 47 current and former officers were investigated by the IOPC after it was revealed at least 1,400 girls were abused, trafficked and groomed in the town between 1997 and 2013.
South Yorkshire Police’s Alan Billings, said: “I am disappointed that, after eight years of very costly investigations, this report fails to make any significant recommendations over and above what South Yorkshire Police have already accepted and implemented from previous investigations some years ago.
“It repeats what past reports and reviews have shown – that there was unacceptable practice between 1997 and 2013 – but fails to identify any individual accountability.
“As a result, it lets down victims and survivors.”