A PREDATORY paedophile posed as a teenager on internet chat rooms to entice as many as 1,700 children all over the country.

Darren Simpson, 32, from Malton, targeted girls and boys for many years by using a false name and pretending to be a young teenager. He has now been jailed for eight years.

He sent the youngsters lewd photos and videos, and persuaded one girl to watch him perform a sexual act on himself on a webcam. He also urged youngsters to send him sexualised pictures of themselves and tried to get another girl to carry out a sex act on herself.

His online crimes lasted 16 years. He was caught out at the beginning of this year following an extensive police investigation involving six forces.

Simpson admitted 32 charges relating to the online grooming of 17 girls and two boys between January and February. Among the charges were 20 counts of inciting a child to engage in sexual activity and ten counts of causing a child to watch a sex act.

Judge Paul Batty QC at York Crown Court described Simpson as “predatory in the extreme”. But Simpson’s alleged wider offending, said to date back to the 1990s, has gone unpunished because other children - possibly as many as 1,700 - haven’t yet come forward.

He said the offences of which Simpson had been convicted were a “snapshot” of his crimes.

Simpson, who worked in retail and was considered “perfectly respectable” until the offences came to light, had asked some children where they lived and suggested to one girl that they meet up, although no meeting ever took place.

Mr Reevell said Simpson managed to hoodwink so many children by alternately posing as a young boy to contact girls, or claiming to be a girl when grooming boys. He often contacted children through their Facebook friends or by masquerading as one of their school friends after snooping on their social-media pages.

Even after some children blocked him from their accounts, he bombarded them with video calls after setting up a fake account.

Simpson admitted spending “every spare moment” of his adult life grooming children.

The mother of one young victim, who lives near York, said her daughter now suffered nightmares after being “violated” by Simpson.

“What Simpson has done has changed her forever,” she added. “She will never be the same again.”

Defence barrister Glen Parsons said Simpson managed to hide his dark secret from family and colleagues who had been “enormously shocked” by the revelations.

Judge Batty told him: “To all the world you led an ordinary and law-abiding life… but you told police that you had been involved in this utterly-revolting activity for most of your waking hours when you weren’t at work.

“The effect of your offending on these children has been profound. As you told the investigating officer, you enjoyed the dominance you believed you had over them.”

Simpson remained expressionless as Judge Batty handed down the eight-year sentence, of which he will serve half, and ordered him to sign the sex-offenders’ register for life.

The judge, who said he would have given a longer jail term but for strict sentencing guidelines, also made a lifetime sexual-harm prevention order which will hamper Simpson’s internet use. It also bans him from contacting his victims or having avoidable contact with children under 16.

Detective Constable Alex George, of North Yorkshire Police, said police inquiries were continuing and that other children would be interviewed.

He said “for sheer scale” it was one of the worst cases of grooming he had ever come across.