Following an announcement by Education Secretary Ruth Kelly that laws preventing sex offenders obtaining work in UK schools are to be tightened up, BBC correspondents report on the safeguards used in other countries.
MATT DAVIS, UNITED STATES
Criminal background checks provide the main safeguard against sex offenders being recruited into US schools.
Megan's Law was named after murdered Megan Kanka, seven
But laws that govern who must be investigated, when and how thoroughly vary from state to state.
In much of the US, checks are made when teachers - or certain other school employees, like bus drivers - apply for jobs or seek teaching certification.
Most states require them to submit fingerprints and other personal data.
This will be checked against the FBI's national criminal records and/or a state-wide criminal database and perhaps against local or national sex offender lists, but there is no standard protocol.
The rules on re-investigating employees also vary.
In Virginia, for instance, teachers sign annual contracts and are rechecked each year.
In neighbouring West Virginia, they get one national-level check when they are certified, have local checks after three and eight years, but are then certified for life.
Other employees like cooks, janitors or volunteers in that state are not required to undergo national, or even state-level criminal background checks.
America is a large country, with a mobile population, and campaigners say more could be done to tighten the rules protecting children within the school system.
The Education Commission of the States (ECS), a think-tank, says "quiet resignations" - where a school employee quits under a cloud but faces no criminal charges - are a particularly intractable problem.
Yet Megan's Law, which compels states to make private and personal information on registered sex offenders available to the public, can act as a further safety net in the US.
State education departments receive a deluge of tip-offs and newspaper clippings from members of the public which in some cases have led to offenders from out of state being identified.
Conversely, the ECS says a growing number of states are now adopting laws that impose penalties for fraudulent - yet career-threatening - accusations against teachers by students.
CHRISTIAN FRASER, ITALY
In Italy there is no national register of sex offenders but criminal record checks are carried out on teachers applying for new posts.
Every applicant must supply a sworn affidavit that they have a clean record.
The Ministry of Public Instruction says that since 2001, 160,000 teachers have been employed in Italy and every application checked against police records.
They point out that almost all teachers in junior schools here in Italy are women, which might explain why there is a low incidence of abuse in schools.
The ministry said it was not aware of any case where a known sex offender had been employed.
But Alberto Gianinni from the Catholic Teachers Association (ADC) questions whether the checks are rigorous enough. "I don't think abuse in schools is widespread," he said, "But it most definitely exists.
"And I am not entirely convinced," he adds, "that every application is checked as thoroughly as it could be."
Mr Giannini has called for tighter guidelines in Italy on the employment of people working with young children.
He points to his own experience as proof that things can and do go wrong.
"At my son's school in Milan," he said "The director was accused of abusing 13 children. He was suspended on full pay and later found guilty.
"But despite his conviction he was allowed to stay at the school - and was later put into an administrative position."
Last year police investigating child pornography on the internet arrested 186 people who had downloaded images from a website that showed girls as young as four being tortured and sexually abused.
A kindergarten teacher was one of those arrested, along with a social worker and three priests.
CAROLINE WYATT, FRANCE
France is currently setting up a database of sex offenders banned from working in schools, but at the moment there is no equivalent to Britain's List 99.
However, some fear that the French list will take at least five years to come into effect fully.
Jean-Pierre Rosenczveig, prosecutor at the Juvenile Court in the Paris suburb of Bobigny and founder of Defence for Children International says until the mid-1980s paedophilia was considered a treatable illness in France and was "not taken as seriously" as it is today.
The French list also includes the names of people who are suspected of paedophile acts, but who have never been charged. Their names can remain in the system for up to five years.
However, teachers in France are not systematically given background checks for criminal behaviour. Such checks apply only to social workers. But if a member of school staff is found guilty of paedophilia, he or she is prevented from working with children.
In France, the most recent criminal cases of child abuse or paedophilia have centred on parents', rather than on school-teachers', behaviour.
In the largest, longest and most horrific child abuse trial ever seen in France, 62 people were convicted in Angers last July of raping, prostituting, molesting or failing to protect 45 children as young as six months. Many were the parents - and some the grandparents - of the children involved.
However, the French public is currently gripped by a televised parliamentary inquiry into how French justice dramatically failed when several innocent people were jailed for several years for paedophile offences, with some having their children taken into care.
Out of 18 people convicted of belonging to a paedophile network in the northern town of Outreau, seven were subsequently cleared in 2004 and six acquitted on appeal in December 2005, while another committed suicide.
The six, including a priest, were cleared by a Paris appeals court after it became clear that a simple abuse case implicating two couples, who had admitted raping or molesting children, escalated into a witch-hunt against neighbours and relatives.
The Outreau case has made France wary of allowing public hysteria to build up over alleged cases of paedophilia.