A predatory paedophile, whose rape victim has never been identified, was today jailed indefinitely.
David Ernest Bye, 43, pleaded guilty to the rape and sexual assault of a girl under 13, and possessing more than 17,000 indecent images of children, some of which he had taken himself, at an earlier hearing at Merthyr Crown Court.
The court heard he groomed multiple victims and photographed himself raping one of them.
Dyfed-Powys Police believe Bye, of Mid-Wales, was the first person to be convicted of rape of a child who has never been identified.
Bye must serve a minimum of five years in jail before he is considered for release.
The matters came to light when Bye, who lived in Mid Wales but worked as an accountant in Reading three days a week, had to call in IT support for a problem with his laptop.
More than 17,000 indecent images of children were found on the laptop, including the most serious category of child pornography.
Of these pictures, he had taken 202 of 10 different children himself.
Some of the pictures showed Bye raping and sexually assaulting a young girl.
Ieuan Morris, prosecuting, said: "The defendant is a predatory paedophile and sexual pervert who secretly engaged in two known acts of sexual penetration with a pre-pubescent girl who was either asleep or for some reason not conscious, at night, in the isolation of his static caravan in Mid Wales.
"From a series of admissions made by the defendant to the police, and his stark declarations to a child protection consultant, he has over some 10 to 11 years harboured a deep-seated sexual craving for young children up to the age of 12 years that continues.
"Furthermore, the defendant has disturbingly expressed a view that he has nothing to lose by further exploiting young girls in this way because his fate is sealed."
Bye was arrested by Thames Valley police on January 21, 2008 but it was Dyfed-Powys Police who recovered a camera containing indecent pictures of children in his caravan and took over the investigation.
Mr Morris said: "The defendant deliberately targeted young, vulnerable single mothers and in one case, a father, with children of their own and befriended them in order that he could prey on the children."
He said Bye was "devious and manipulative" and used his own young daughter as a means of gaining access to other children.
There is no suggestion his daughter herself was a victim.
Mr Morris said Bye groomed the children by lavishing gifts on them.
"He was attracted to both young girls and boys, whom he took into his confidence," he said.
"Over a period of 12 months or more, the defendant collected and downloaded on to a home computer 17,636 pornographic images of children between the ages of six and 12 years of age for the purposes of stimulating his craving for paedophilia.
"This is unquestionably an unusual and most serious case, perhaps unique, in that direct evidence of his two known acts of sexual penetration are against an unknown female under the age of 13 years."
Mr Morris said: "Under the guise of being a friendly and charming man with a sympathetic ear to the difficulties encountered by single parents who had been engrossed in troubled relationships with former partners, and with the blithe assistance of his own daughter, he soon turned his attention away from the parent and to their children."
The court heard Bye was originally from Greenford, west London, and lived in Scotland, Basingstoke and Canterbury before settling in Mid Wales.
Mr Morris produced evidence from parents of three girls and three boys Bye befriended.
He took one victim swimming and bought her a bike. He bought another girl a plastic horse, and bought a boy a remote control car and model aeroplane.
Ian Ibrahim, defending, said Bye was "a man of some intelligence" who knew handing his laptop over to IT would lead to his being found out.
He said: "He could have walked out with the computer but he didn't. He wanted this to stop."
Mr Ibrahim said that while on bail following his initial arrest in January 2008, Bye sought voluntary help for his deep-seated problem.
Sentencing Bye, Judge Eleri Rees imposed an indeterminate sentence for the protection of the public.
She said he must serve at least five years before he is considered for parole but would be on licence for the rest of his life and could be recalled at any time.
She said: "Over a period of 12 years you developed an obsession with viewing images of pre-pubescent girls. That behaviour escalated to taking photographs yourself... then graduated to touching the children and actual rape and penetration."
How he managed to do this without the child waking "is a mystery and will remain so", she said.
The judge said that despite his admissions to police and pleas of guilt, he had not assisted officers in identifying the children involved so they could receive help.
"You cannot assume that because the children were young they are blissfully unaware of what occurred," she said.
Talking about a letter Bye had sent to the court, she said it was clear he remained in denial as to the extent of his obsession.
"You have a long way to go in actually addressing your distorted thinking and attitude towards children and sexual matters," she said.
Bye was disqualified from working with children indefinitely and must register as a sex offender for the rest of his life.
Detective Inspector Diane Davies, who led the investigation, described Bye as a chameleon.
She said: "He has the ability to engage himself with various groups of people from all walks of life, to fit in and get respect.
"It has been an unusual case and it's been very, very challenging. I think we can't change the past, we can't take away what has happened to these children, we can only change the future and the future is that David Bye will not pose a risk to children for many years to come.
"There is every possibility there are other victims out there and we would urge them to come forward. David Bye hasn't woken up one day thinking, 'I want to rape a child', he has fantasised about it and built up to it."