An 18-year-old who molested a toddler and a schoolgirl while building a library of vile child porn images has walked free from court.

Sick Matthew Thain collected internet pictures of children as young as four being abused by adults, as well as extreme animal pornography, but was spared jail after a judge deemed supervision and a sexual offences prevention order would be enough to protect other children.

The teenager, from Violet Lane in Croydon, took photographs of the ten-year-old girl in provocative poses to satisfy his “sexual interest in children”, Southwark Crown Court heard on August 6.

Judge Anthony Leonard QC said: “I cannot begin to understand what went through your mind to make you think it was appropriate to touch that 10-year-old as you did, or how you thought it was right to play with the genitals of a child who was three.

“I cannot begin to understand why you downloaded horrid photographs of things being done to very young children.

“It is hard to think that your relatively young age can explain or in part excuse your actions and I can only hope that now you have been brought before the court and begin these sentence for the offences that it dawns on you how wrong your behaviour was.

“The decision I have to make is stark - should I protect the public by putting you in a cell for a few years? Or shall I concede to your counsel’s argument that you should get help in the community?

“I have decided that children would be protected if you were to get help as suggested.

“In my opinion your offence is serious enough to warrant a community order.”

Thain was arrested by vice squad police hunting for child porn on his computer at the family home in April last year.

He admitted molesting both girls in January and the summer last year, while analysis of his computer revealed 766 indecent images - 125 of which were short films.

Harry Potter, defending, said Thain had an extremely traumatic childhood and was of a low IQ.

The teenager, who wept openly throughout the hearing, was given a three-year supervision order, a youth offending programme, and a residency and sexual offences prevention order.

He admitted four counts of sexual assault on a child under 13, two counts of making indecent images and one of possessing extreme pornography.