A paedophile who posed as a young girl online to persuade boys to perform sex acts on webcams has been sentenced.

Harry Johnson, of Hunter's Lane, Watford, will spend six years in a young offender’s institution after pleading guilty to 22 charges.

Four were causing or inciting a child under 13 to engage in sexual activity, seven were causing or inciting a child to engage in sexual activity, two of causing or inciting sexual exploitation of a child. Six were of taking indecent photographs of a child and three were of possessing indecent images of a child.

The 19-year-old civil engineering student exchanged explicit messages and sent them images of girls before he recorded them engaging in “sick and degrading activity”, St Albans crown court heard on Wednesday.

Prosecutor Simon Wilshire said: "Over a period of a time, between January and July 2016, he posed on the Internet as a young female.

"He made contact with a number of young boys ranging in age from 11 to 15 or 16.

"He posed as a young girl and incited them (the boys) to engage in sexual activity over the Internet. At times he recorded the activity that was going on in front of him.

"Not only had he duped and misled young boys to commit sex acts at end of web cam, he recorded videos videos and stored them."

Johnson called himself Melissa, Amie or Becca as he groomed seven young people aged between 11 and 16.

When police raided his home in Watford in July last year they found that the student had stored the recordings on his computer, where he had also downloaded child sex abuse images and videos at Category A, B and C.

The court heard Johnson was caught when the parents of one of the victims "exercised due diligence" and checked what their son had been doing on his iPad. They found private messages with someone called MelissaB178.

Mr Wilshire said: "They challenged him and he admitted he had been sending explicit texts and had used the webcam. He was embarrassed, ashamed and upset.

"The parents reported it to police, who were led to Johnson's home address."

When Johnson's computer was examined they found he had recorded six other boys performing sexual acts.

Mr Wilshire said over 600 Category A, over 650 Category B and more than 3,000 Category C indecent images and videos of children had been downloaded by Johnson onto his computer.

Defending, Franco Tizzano said Johnson had been the victim of abuse himself.

"He was a normal young boy who had been friendly, kind and considerate, but he changed as a result of the abuse he received," said Mr Tizzano.

He said on his arrest he showed instant remorse for what he had done.

In a note read to the court Johnson said: "I am truly sorry to the people I targeted and the people I hurt as a result of my actions. I was thoughtless and selfish. I know I can't undo what I have done."

Judge Stephen Warner told him: "The seven young people were young and vulnerable. You took advantage and exploited them for your own sexual gratification.”

He ordered the forfeiture and destruction of Johnson's computer and memory sticks.

Johnson must also abide by the terms of a Sexual Harm Prevention Order for six years and register as a sex offender indefinitely.