By Michelle Roberts
BBC News health reporter
Abuse is common but under-reported
Professionals must not be too reluctant to remove children from abusive parents, a group of experts has said.
The call comes in a series of articles on child abuse published in the Lancet medical journal.
The studies also claim that 10% of children in wealthy countries suffer ill-treatment every year, but that neglect and abuse are under-reported.
The findings come as child protection services in the UK are stepped up in the wake of the Baby P case.
One study in the Lancet's Series on Child Maltreatment, says that one in 10 children in high income countries is maltreated - but that only a tenth of these are investigated and even fewer removed from danger.
Maltreatment includes hitting, punching, burning and serious emotional abuse as well as sexual abuse. In the UK it is estimated that one million children are affected each year.
The author says "it is estimated" that at least 15% of girls and 5% of boys have been exposed to sexual abuse of some kind by the age of 18, and that 5-10% of girls and 1-5% of boys are exposed to penetrative sexual abuse.
We have to ensure we are taking children away from dangerous situations
Professor Jane Barlow, professor of public health at Warwick University
Child abuse is grossly under-reported - even by the schools and community health services that have continuous contact with children - another study says.
There is a reluctance by professionals to intervene when they suspect abuse for fear of doing more harm than good and being accused of breaking up families, according to the experts.
Professor Ruth Gilbert, a child health expert from University College London, said: "Scarce reporting to child-protection agencies is a cause for concern, and we need to find out whether maltreatment is being recognised and dealt with in other ways."
Professor Jane Barlow, professor of public health at Warwick University, says there is a strong argument for removing children from dangerous homes.
There is evidence that removing the child from the dangerous environment and placing them in care can be beneficial, she adds.
Professor Barlow insists: "We have to ensure we are taking children away from dangerous situations. Removing a child is likely to have better outcomes.
"We currently attempt to reunite 50-75% of children that have been removed. Up to half end up back in foster care."
But she warns that social services would be overwhelmed by demand.
"If you lower the threshold, the number of children being removed is going to increase considerably and social services will be overrun."
She also said the onus should be on teachers, GPs and community health workers to raise the alarm if they saw signs suggesting abuse.
Another of the studies' authors, Professor Cathy Spatz Widom, of the City University of New York, says: "There's a perception by the public and by some professionals and policy makers that placing children in foster care is a bad thing.
"By looking at the empirical evidence, it's a more complicated story. We should not just dismiss foster care."
Professor Gilbert said there would have to be certainty that a child was being maltreated before taking them out of their home.
John Simmonds, of the British Association for Adoption & Fostering, said there was a danger of going too far.
"Most certainly some children are better off separated from their parents, and this probably isn't happening as much as it needs to be. Baby P was one example of that.
"But foster care is not a perfect solution. There is such an atmosphere of blame and recrimination at the moment, with social workers and parents watching their backs.
"I do worry about the consequences and things swinging too far the other way."
Dr Patricia Hamilton, president of the Royal College of Paediatrics and Child Health, said: "It is sometimes extremely hard to make judgements in child abuse cases.
"Our society has to accept that child abuse happens and that paediatricians and social workers have a duty to act when they suspect any forms of maltreatment."
Baby P died with multiple injuries, despite receiving 60 visits from welfare professionals.
Last month, the 17-month-old's mother, her boyfriend and a lodger were found guilty of causing the child's death.