Police failures to take child protection seriously could lead to a repeat of the horrifying abuse scandals seen in Rotherham and Oxford, the chief inspector of schools has claimed.
Ofsted boss Sir Michael Wilshaw said that there are "serious weaknesses" in how a string of forces deal with the issue in a damning letter to police watchdog chief Sir Tom Winsor.
He wrote: "My worry is that if chief constables fail to give this issue sufficient priority, we may see a repeat of the sort of catastrophic failings we saw a few years ago in places like Rotherham, Oxford and elsewhere."
A report found that in Rotherham 1,400 children were systematically sexually abused between 1997 and 2013; while in Oxford more than 300 were violently abused and tortured over more than 15 years.
Accusing some forces of failing "to take their child protection responsibilities seriously", Sir Michael said that more than half of Ofsted's 42 inspections of local authority children's services in 2015/16 revealed "serious weaknesses" in police contributions to protecting youngsters.
There were cases where forces were not quick enough in telling social workers when children went missing, Sir Michael said, and officers had failed to attend key meetings about child protection, or visits with social workers. In a number of forces there were delays in flagging up domestic abuse cases to the local council.
Sir Michael said that the "most serious concerns" were raised about Cleveland Police's support for children's services in Stockton-on-Tees.
In one case, the Ofsted inspector questioned a police decision to close a case even though "there was clear evidence that the children concerned had suffered non-accidental injuries".
The investigation was re-opened after the local council intervened when Ofsted raised concerns.
Officers were often unable to attend meetings about children potentially at risk of serious harm, and therefore intervention plans could not be agreed, and had been told not to go to meetings about unborn children.
The inspectors found "an unacceptable and potentially dangerous gulf between the stated priorities of Cleveland Police in relation to its support for child protection and the practice observed in the course of the inspection of the local authority's children's services".
Elsewhere, issues highlighted included in Southend, where social workers were left alone on "potentially dangerous child protection visits", and were unable to remove children from the home without police officers present.
In Torbay, officers took children into police protection without telling social workers; and in Dorset, a backlog of criminal records checks led to delays in allowing families to adopt.