Private schools are making hundreds of thousands of pounds from Vietnamese children who are entering Britain on student visas then disappearing, it has been revealed.

Children thought to be as young as 15 are being brought to the UK by suspected trafficking gangs through legitimate visas sponsored by elite private schools, an investigation by the Times found.

The students often go missing, in some cases disappearing without a trace, within weeks of starting at the schools. It is believed they are victims of trafficking gangs who have exploited a loophole in Britain’s visa rules to bring minors into the country.

The investigation carried out by the paper uncovered at least 21 Vietnamese children who have vanished from boarding schools and private colleges across Britain in the past four years. The investigation was carried out without the schools' knowledge.

The children - who are mostly girls - are feared to have been trafficked into brothels, cannabis farms or nail bars.

Police and the Home Office are investigating the disappearances, but many of the girls remain unaccounted for.

Eight Vietnamese children have gone missing from the £25,000-a-year Chelsea Independent College, a west London school owned by Astrum Education, a for-profit body.