Council officials said they did not know that Baby P's mother had a boyfriend
Key details that might have saved the life of Baby P were revealed by his own mother on videotape - but never passed to police, the BBC has learned.
Panorama has found that the baby's mother told a social worker about the new man in her life four months before the child was found dead.
That man, her 32-year-old boyfriend, was found guilty of causing or allowing the toddler's death.
The same man, who cannot be named, was also convicted of raping a young girl.
A jury at the Old Bailey found the boyfriend guilty on Friday of the rape of a two-year-old girl, but acquitted Baby P's mother of child cruelty charges.
Despite being on the at-risk register of Haringey Council in north London, Baby P - who can now be identified as Peter - died, aged 17 months, in his blood-splattered cot on 3 August 2007.
He had more than 50 separate injuries and had been seen on at least 60 occasions by professionals from social workers to health professionals to police during the eight months that he spent on the child protection register.
Police not told
In Baby P: The Whole Truth?, Panorama reveals that his 27-year-old mother, who also cannot be named and who has admitted the charge of causing or allowing the toddler's death, was the subject of a lengthy videotaped interview conducted by a social work manager in Haringey.
Panorama has learned that the videotape, taken in March 2007 as part of a pilot scheme for a new therapy method, includes details about her new "friend" and how she feels about him.
Despite the presence of a new adult in the child's life, those details were not handed over to police investigating suspicious injuries to Peter at that time.
They also were not disclosed to police in August 2007 when they began their investigation into the child's death, or the serious case review team sent in to examine how the child was protected by Haringey.
A retired senior police officer tells Panorama he is convinced that if the police abuse investigation team had been alerted, the boy's life could well have been saved and there would have been no need for a murder inquiry.
Haringey Council has told Panorama that its former head of children's services, Sharon Shoesmith, and her deputy, Cecilia Hitchen - both since dismissed - were responsible for handing over any relevant documents and information to investigators.
Mrs Shoesmith has told the BBC that she cannot comment on the videotape.
On the disclosure of documents she said: "This is always done in line with the advice of lawyers and in this case with a barrister.
"Everything was disclosed with only those documents that our barrister advised were subject to Public Interest Immunity withheld and the Crown Prosecution Service would know what they are".
Ms Hitchen declined to comment.
Mrs Shoesmith was suspended by Children's Secretary Ed Balls in the aftermath of the Baby P court case last November and has since been fired from her position, along with four others in her department.
Haringey social workers maintained that Baby P's mother had appeared to be co-operating with them and deliberately hid her violent boyfriend from them.
In an interview with Panorama, Baby P's maternal grandmother says she too alerted Haringey social workers to the existence of the new boyfriend shortly after the baby was first placed on the child protection register in December 2006.
The grandmother labelled her daughter "manipulative" and said her boyfriend was obsessed with violence.
"Everything he talked about was violence, that's all he ever talked about in my company was violence," she said.
Panorama has also seen police documents that show the social work manager who videotaped Baby P's mother was directly involved in the decisions about his case.
The notes show that officers told her they wanted the baby removed from the house until all the injuries were explained and were baffled when that did not happen.
The baby's clothes were badly stained with blood
A senior officer wrote in his log: "This situation cannot continue."
He goes on: "I am at a loss as to why our position is at variance to that held by social services. Our concerns for Baby P are valid."
Sources have told Panorama that the pilot scheme that focused on the parent's future wishes would have been one of the considerations in how to proceed with the case.
In a statement Haringey Council told the BBC that the therapy - known as Solution Focused Brief Therapy - was inappropriate in the case of Baby P.
One international child protection expert has told the BBC that, used in isolation, the therapy could prove dangerous as the focus shifts from the child at-risk to the parent, potentially causing social workers to lose sight of their priorities.
Mr Balls told Panorama he hopes that an improved inspections system including unannounced audits of children's services across the country will help ensure that mistakes such as those made in the Baby P case are not repeated.
"Will it bring back the little boy who died in Haringey? No, I can't do that. But can we try to make sure that we don't repeat that kind of tragedy in the future? Yes, we can."
Panorama's Baby P: The whole truth?, Monday, 4 May on BBC One at 2030 BST.