A PAEDOPHILE was arrested at Heathrow Airport as he returned to the country from New Zealand three years after sexually assaulting six young girls.
Student William Key preyed on girls from four different families over a five-year period.
But the abuse did not come to light until two of the victims, who were sisters, wrote a letter about Key to their parents.
Detectives discovered the 31-year-old had emigrated to New Zealand, but after contacting officers there they found out he was expected to return to the UK.
Police were at the airport waiting to arrest him as he got off the plane.
Yesterday, he was jailed for seven years for offences against young girls.
Three of the families involved were from Derby.
When arrested, Key admitted sexually touching the sisters, who were aged between 11 and 13 at the time.
He then confessed to the assaults on four other victims. These girls were aged four, six, ten and 12 when he abused them, Derby Crown Court was told.
Prosecutor Sarah Slater said the mother of the sisters found their letter after they had gone to bed one night in February this year.
After reading the contents with a growing sense of horror, she said she felt “sick and extremely guilty and upset”.
The mother said Key had acted in a “devious and manipulative manner”.
Miss Slater said Key had abused the girls with varying amounts of seriousness, from touching them inappropriately over their clothes to touching beneath the clothes, in the case of one child.
The court heard that Key had sent suggestive MSN messages to two of the older girls.
To another child he sent texts asking her “whether she would ever get with him”, to which she replied “no”, said Miss Slater.
The court heard that Key indecently touched the four-year-old while playing a game with her, where he had picked her up and spun her around.
Sentencing Key for the catalogue of abuse, Judge Michael Fowler said: “You preyed on these young girls.”
He said it was clear the girls’ parents had invited Key to their homes because he was “socially isolated” after he moved to Derby to study at the university.
Judge Fowler said: “They went out of their way to help you integrate into the community and you abused that.
“On occasions you were given access to their children and you took advantage of that and to varying degrees you abused these children.”
Key admitted 16 charges of sexually assaulting a child.
Justin Ablott, speaking for Key, said: “The most serious allegations arrived here at court because of the admissions he made and were from victims the police were unaware of.
“Mr Key has made the point that in many ways he was glad he had been confronted by the police about his behaviour.”
Mr Ablott said Key, whose home address was given as Newton, New Zealand, was genuinely remorseful.
Key must sign the sex offenders’ register and was banned for life from working with children.
When he is released from prison, he must obey a sexual offences prevention order, which includes not being alone with girls who are under the age of 16 and not going within 50 metres of a nursery, school or college.
After the sentencing, a police spokeswoman said that, when the offences were initially reported, officers contacted police in New Zealand and asked to be informed if Key ever tried to leave the country.
New Zealand police alerted officers in Derbyshire after Key boarded a plane to the UK.
It was not said in court why he flew back to Britain.