Baby P suffered 50 injuries before his death in August 2007
Over 80% of children killed or seriously hurt through neglect or abuse were not on England's child protection registers, it has been reported.
Only 33 of the 189 children whose death or injury in 2005 to 2007 led to a review were on the registers, according to figures obtained by the Guardian.
The figures follow the outcry over Baby P, who died in 2007 after severe abuse.
A government spokeswoman said a report on children's safeguards had been ordered in the wake of the Baby P case.
The Guardian figures come from unpublished government-commissioned research.
It said children who died from broken ribs, smashed skulls and forced starvation were all missed off the register of children known to be suffering harm.
Only 33 of the 189 children whose death or injury prompted a local authority serious case review in the two years from 2005 to 2007 had been on the register, it said.
It said medical staff and social workers had seen evidence of abuse, but local authorities had not added the children to the list.
Marion Brandon, a University of East Anglia academic who is leading an analysis of the serious case reviews, told the newspaper social workers often struggled to respond appropriately.
"They make an early assessment and don't tend to change their minds", she said.
"They keep looking for evidence that supports their view and that can be very dangerous.
"They might stick to saying it is a case of neglect when it is actually abuse."
A spokeswoman for the Department of Children, Schools and Families (DCSF) said she could not confirm the newspaper's figures as the report had not yet been published.
But she added that early findings suggested that the majority of children subject to serious case reviews had not been given a child protection plan.
"This could be because they were not known to children's services, or there was no evidence at that time to suggest they were at continuing risk of harm," she said.
"However, all agencies working with children should be clear about their responsibilities for safeguarding and promoting the welfare of children.
"Where there is evidence of continuing harm the child should be made the subject of a child protection plan and action taken to safeguard them."
She added that Ed Balls, Secretary of State at the DCSF, had instructed Lord Laming to report on progress in implementing safeguarding arrangements for children in England in light of the Baby P case.
And Sarah Harman, a family lawyer with 30 years experience, told the BBC's Today programme that over-criticising the system could result in more children being unnecessarily being taken into care.
"If you're not careful, we'll create problems, we create backlashes - which is that social workers become risk-averse," she added.
"Child protection is not easy. It's not easy to identify the families who are going to kill their children."
Baby P, from Haringey, north London, died at 17 months after suffering 50 injuries.
Two men and his mother have been convicted of involvement in his death and have been told they face "substantial" terms in prison.
The director of Haringey's Children and Young People's Service has come under increasing pressure this week to resign.
However, 68 Haringey head teachers have now written a letter in support of Sarah Shoesmith, saying she has "worked relentlessly" to ensure the best services for "all young people".
An internal inquiry by Haringey's Local Safeguarding Children Board (LSCB) blamed legal advice taken a week before the baby's death for the decision not to take him into care.
It found "numerous examples" of good practice in the case although there had been "weaknesses" in information flow.
Meanwhile Baby P's natural father has paid tribute to the police for their part in bringing the case to court.
He also thanked the social workers who had been involved since his son's death. He described them as acting with "professionalism and courtesy".