A complaint about the speed with which South Wales Police responded to the abduction of a child by a convicted paedophile has been partially upheld.
The Independent Police Complaints Commission has said officers may have been able to prevent part of the three-year-old's "terrifying ordeal".
Craig Sweeney took the child from her Cardiff home in January and seriously sexually assaulted her.
The child's family said it would launch a civil action against the police.
The IPCC has recommended that certain officers face a misconduct panel.
Describing Sweeney's crime as "monstrous", IPCC Wales Commissioner Tom Davies said had there been prompt and appropriate action by officers, part of the child's ordeal may have been prevented.
The child's ordeal began in the Rumney area of the city on 2 January.
Sweeney had just finished a period of being on licence after early release from prison for indecently assaulting another child, aged six.
Sweeney had called at the child's family home in Rumney
The toddler's mother, who had known Sweeney when she was younger, had not long returned from a shopping trip when he knocked on the front door.
She invited Sweeney in and as she went into the kitchen, he snatched the child, and drove her to his flat in Newport where he sexually attacked her.
Moments later, at 2227 BST, the mother made a frantic phone call to police and gave Sweeney's name and address in Newport, some nine miles away.
Mr Davies said: "It is known that he subjected her to further terrifying ordeals between the time he left the house which was sometime around 0010hrs and his subsequent arrest at around 0128hrs."
But he said while the investigation considered there may have been potential to go to Sweeney's home sooner, it found insufficient evidence to substantiate the claim that this would have prevented the serious sexually assault that took place there.
Sweeney was eventually caught by chance by traffic police in Wiltshire in the early hours of the following morning after overturning his car - having thrown his victim from the vehicle moments before.
Going back to the subject of officers' actions, Mr Davies said "everyone makes mistakes but for the police these can have huge consequences as we have made clear today".
"After lengthy consideration of all the facts, I have decided to refer the conduct of officers to the chief constable.
"It will be for the chief constable to balance the expectations South Wales Police would require of officers with this level of seniority and experience against the circumstances described above in terms of the incident and the practices prevailing at the time."
He added that one of the officers who had since retired would not be subject to any further action, given that none of these alleged actions are in any way subject to criminal proceedings.
Chief Constable Barbara Wilding said the report's recommendations would be carefully considered and she apologised to the child and her family for letting them down.
"On the night we did not operate to the usual high standards that we set ourselves," she said, adding that there was no evidence to suggest anyone acted with anything less than the best of intentions.
The recommendations for South Wales Police are:
Immediate action to sharpen and clarify their policies on dealing with this type of incidentImprove awareness at appropriate levels through training and live exercise of procedures for following these policiesConsider methods of improving the access appropriate personnel have to the intelligence systems available to force whilst dealing with such incidents
Recommendations to Acpo, and her Majesty's Inspectorate of Constabulary:Consideration that they revisit policies and monitoring of the systems dealing with registered sex offenders.
Sweeney was jailed for life in June after admitting four charges of kidnap, three of sexual assault and one of dangerous driving.
But there was political controversy after Sweeney was told he could apply for parole after five years and 108 days.
Home Secretary John Reid asked the attorney general to appeal the case but Lord Goldsmith concluded the law had been applied correctly by the judge.