Social services staff asked to make decisions about the future of five children were involved in an attempted "cover-up", a family court judge has said.
Judge Mark Horton said there had been a "deliberate and calculated" alteration of a social worker's report.
The judge said the report had been altered by another social worker and a team manager.
He said the original report - an assessment of the children's parents - had contained "positives and negatives" and had been balanced.
The changes completely altered the tenor of the report and created a picture that was "wholly negative", he said, and the alterations had the effect of improving the case for removing the children from their parents.
Judge Horton said the family could not be identified, but he said social services staff involved worked for Hampshire County Council and he named a number of people.
The judge has outlined concerns in the latest in a series of rulings on the case following family court hearings in Portsmouth, Hampshire.
Judge Horton said the children involved were aged between 16 and three.
Proceedings had started more than two years ago.
He said the children were living with foster carers as part of an interim arrangement.
Social services bosses wanted them to stay in foster care in the long-term. The parents wanted them returned to their care.
Judge Horton said he had concluded that the children should stay in the care of Hampshire County Council and approved fostering plans put forward by social service staff.
But he was critical of the way the case had been handled.
"A final decision is long overdue," said Judge Horton.
"The reasons for the delay have been almost exclusively, the actions of employees of the applicant local authority."
The judge said he hoped that the case was unusual. "I certainly have not previously come across one quite like it," he said.
"It is exceptional to find a case in which there has been deliberate and calculated alteration of a report prepared by one social worker in order to make that assessment seem less favourable, by another social worker and the team manager; the withholding of the original report when it was ordered to be disclosed and the parties to the alterations lying on oath one of them twice, in order to try to cover up the existence of the original report."
He said given the "enormity" of what staff had done and the fact "they still work as social workers" it was right that they should be named so that members of the public were aware of "their shortcomings in this case".
The judge indicated that some staff had left Hampshire council and moved on to other jobs since the case involving the five children had started.
Social worker Sarah Walker Smart had "lied twice to me on oath", said the judge.
He said he had been told that she had been promoted to a "team manager" in Hampshire council.
Kim Goode had been Sarah Walker Smart's manager and "was the person who initiated the wholesale alteration of the original report and who attempted to keep the truth from the parties and me", said the judge.
He said she had gone on to become "district manager for the Isle of Wight".
Lisa Humphreys had been Kim Goode's manager, said the judge.
"Her evidence was deeply unimpressive," he added.
"She made a 'hollow' apology to the parents during her evidence; she regarded a social worker lying on oath as 'foolish' and she failed to accept any personal responsibility for what had gone on under her management."
He said she had gone on to become assistant director of children's social care with Lambeth Borough Council.
Judge Horton said he had concluded that at one stage the children had been illegally removed from their parents' care - and that a "fair parenting assessment" had not been carried out.
He said a number of concerns had been raised about the way the children were being looked after by their parents.
The judge said the parents loved their children - and their children loved them.
But he said despite the quality of those relationships, the parents had "difficulty parenting the children to the required minimum standard".
He said both parents had experienced "very difficult childhoods", had an underlying "chronic" mistrust of professionals and did not want to "inflict on their children the experiences they themselves had as children".
"These factors led the parents to fail to provide effective boundaries for the children," said the judge.
"From this flowed ... significant harm."
He added: "This inability to set consistent boundaries had led to appalling neglect of the older children's educational, emotional and social development and neglect of all of the children's health needs.
"The family home had at times been of a standard that fell below that required to meet the children's basic needs.
"The younger children were at risk of suffering similar significant harm unless the state intervened."
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