The UK is supposed to have some of the toughest paedophile laws in the world, but the men exposed in this programme have all found loopholes which allow them back into positions of authority over children.

One man was convicted of serious child sex offences whilst a teacher in Australia.

He returned to the UK and became a teacher again, having avoided the sex offenders register because his crimes were committed abroad.

Another offender is also a teacher, this time a private tutor who gives one-to-one lessons in his own home.

Whilst the team were secretly filming, they saw a paedophile leading a young boy into his house. They called the police, who found the boy in the offenders bed.

Presenter: Paul Kenyon
Producer: Kate Middleton