The first pictures of Baby P were revealed on Friday
Gordon Brown has vowed to do everything in his power to prevent a repeat of the Baby P abuse case.
The prime minister rejected Tory claims of "buck-passing" after it emerged that a whistle-blower had raised concerns about Haringey Borough Council.
Baby P's natural father said the process had been "very traumatic", adding: "I loved him deeply."
Baby P died aged 17 months following abuse. His mother and two men were convicted of causing his death.
The alleged failings were investigated by the Commission for Social Care Inspection (CSCI).
Six months prior to his death concerns about Haringey Council's child protection were examined by the CSCI as a result of the letter written to ministers by the whistle-blower.
Speaking in New York ahead of a global summit on the financial crisis, Mr Brown said he would do "everything in my power" to prevent a repeat of the case.
Gordon Brown says a Baby P case 'must never happen again'
"I am determined that everything we do, the inquiries we are having in this case, reveal everything that went on," he said.
In a statement read by solicitor Chris Yiannakas, Baby P's father condemned those responsible for his son's death.
"Those who systematically tortured P... kept it a secret - not just from me, but from all the people who visited the house.
"Even after he died, they lied to cover up their abuse."
A lawyer acting for former Haringey social worker Nevres Kemal sent a letter about her concerns over the council to the Department of Health in February 2007.
She was worried that children in the borough continued to be "at risk".
This was despite an inquiry into the killing of eight-year-old Victoria Climbie - she died from abuse and neglect in the same borough eight years ago.
Ms Kemal believed recommendations made by Lord Laming following that inquiry were still not being followed.
Her letter was passed to the Department for Children, Schools and Families (DCSF), which said proper procedures were followed.
Lawyer Lawrence Davies: 'We had been pushed from pillar to post'
Haringey Council has issued an injunction against Ms Kemal so that she cannot talk directly about the case or anything to do with "child protection matters".
She is now pursuing a claim of constructive dismissal from the council.
The DCSF confirmed it received a letter dated 16 February 2007 containing allegations "that child protection procedures were not being followed in Haringey".
A spokesman claimed "standard procedures" were followed and after the letter went between various departments, Ms Kemal was told to notify the CSCI as it would take "appropriate action".
It is not thought that ministers saw the letter, and BBC home affairs editor Mark Easton said it appeared to have failed to reach the people who could have acted upon it.
He said: "When the letter was sent back in February 2007 the then body that was looking after inspecting children's services in England was the Commission for Social Care Inspection.
"Ofsted, perhaps surprising to some people, actually took over the inspection of children's services in April 2007 and what they say is that only ongoing complaints that were still live - as it were - were passed to them.
"They only received paper details from the commission and I think there is a suggestion that in a way this complaint fell through the gap - that somehow concerns about what was going on in Haringey were not passed on to the body which was responsible for inspecting them."
Ms Kemal's lawyer, Lawrence Davies said: "If the social care inspectorate had acted on it or the ministers had acted on it [the letter], it seems hard to believe that the situation in which Baby P was seen 60 times in total... presumably several times after February, couldn't have been averted."
The CSCI said it did investigate the claims and "was satisfied that the council had dealt properly with the individual case raised by Ms Kemal".
The body also said it - in conjunction with Ofsted - had identified broader areas where improvement was needed and ordered the council to make changes.
Its statement added: "The transfer [of responsibility to Ofsted] included the handover of all previous case files, inspection reports, databases and all of our staff working on children's services."
Public inquiry call
The shadow children's secretary, Michael Gove, said no government department appeared to have been willing to act on the warning.
He said: "The public are tired of hearing that 'correct procedures have been followed' when a child died in agony.
Ministers were warned about child protection issues in Haringey last year
"Ministers were told six months before Baby P's death that there were profound problems in Haringey's children's services department.
"Yet all that appears to have happened is the... gagging of the whistleblower and bureaucratic buck-passing in Whitehall."
Local Lib Dem MP Lynne Featherstone wants a public inquiry and she told the BBC that someone at the council should take responsibility.
No-one at Haringey Council has lost their job over the case.
The council welcomed a government review, saying it would be "open and co-operative" with inspectors and would implement the findings "swiftly and comprehensively".
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