The Guardian story came from information leaked from a intelligence report by the UK’s Border and Immigration Agency.
Of the 77 children who have gone missing, only four have been found. Two of the girls who returned had been exploited for one year in brothels in the Midlands.
This case is part of a wider UK problem of young people who are trafficked into the UK and then go missing from local authority care. Last year, a survey by the CLA revealed that 100s of children have gone missing from care over the last five years and have never been traced. A significant number of these young people are unaccompanied asylum seekers and the likelihood is that many of those young people are victims of trafficking. You can read more about our survey here.
You can read the full story about this incident in the Guardian.