Of all the cases found during a Home Office-sponsored project, only three had been reported to the police. One girl had been subjected to satanic abuse, Avon and Somerset Police found, while others had been raped, starved or exposed to domestic violence and illegal drugs.
A group of Russian students were left homeless without money, while one child was forced to sleep in an under-stairs cupboard and another slept in the bath.
One 13-year-old British girl visiting France was sent with her exchange partner each night to sleep in an empty house next door, the police found. She was sexually assaulted and has since attempted suicide several times.
Language schools, which bring about a million young visitors to Britain each year, are not allowed to make checks on staff or on host families unless the students are staying for more than 28 days.
Now, after a campaign by Avon and Somerset police and by a Liberal Democrat MP, Dr Peter Brand, the Home Office says the rules are to be changed.
A register of sex offenders which could be drawn up under a review launched earlier this year would be available for checks on families and teachers meeting children during their stay in Britain. A new criminal offence under which sex offenders who try to work with children could be charged would also help, the Home Office said yesterday.
The Avon and Somerset research has been carried out by Chris Gould and Kaye Jones, two vice squad officers who discovered that a known sex offender had been hosting children from abroad for three years. They received a pounds 20,000 grant from the Home Office for the study.
More than half the cases they looked at happened after children were placed by commercial language schools, while others included cultural exchanges and language trips abroad. These schools often advertised in local newspapers for hosts who then receive a small fee. One advertisement read: "Come and choose your child from one of 21 nations."
No one checked whether the hosts had criminal convictions, whether the houses were safe or whether the children were likely to suffer racial abuse from their hosts, Detective Inspector Gould said.
"You wouldn't send your child to a house at the end of your street if you knew nothing about the person living there, yet on the strength of a glossy brochure... we send our children thousands of miles across the world to stay with strangers.
"The companies that abuse this blind trust cannot be allowed to continue to profit from it and we must all take responsibility for the care and safety of our young people," he said.Reuse content