More than one in 10 British children aged 12 to 13 have made a pornographic video, according to a survey for children’s charity the National Society for the Prevention of Cruelty to Children (NSPCC). A further one in 10 are also worried they may be addicted to porn, while a fifth said they had seen pornographic images that “shocked” or “upset” them.

Dame Esther Rantzen, founder of the NSPCC’s ChildLine service, said that children as young as 11 had contacted them with concerns about online pornography.

“Young people are turning to the internet to learn about sex and relationships,” she said.

“We know they are frequently stumbling across porn, often unintentionally, and they are telling us very clearly that this is having a damaging and upsetting effect on them.

“Girls in particular have said they feel like they have to look and behave like porn stars to be liked by boys.

“We absolutely have to talk to young people about sex, love, respect and consent as soon as we feel they are ready, to ensure that they gain a proper perspective between real life relationships and the fantasy world of porn.”

The report includes a variety of quotes from unnamed children who speak of the effect pornography is having on them. One girl said: “I can’t stop thinking about the sex scenes I saw in a porn film. I think I’ve become a bit obsessed. All I do is fantasise about the stuff I saw – like being tied up. I know it makes me sound a bit weird but I can’t help it.”

ChildLine even said that some children had contacted them to say they had deliberately looked at child abuse images:

“There was a small number of young people who told ChildLine that they had deliberately searched for child abuse images or were actively posting and saving child abuse images online. These young people talked about the shame and disgust they felt, and most of them admitted that they knew the material they were accessing was wrong. They said they couldn’t lose their interest in it and went to great lengths to view the material in private and clear their internet history so nobody would find out what they were doing.”

Peter Liver, director of ChildLine, said that children had reported feeling depressed after watching porn, with some saying it gave them body image issues and put pressure on them to engage in sex acts.

“The Government recently proposed plans for children aged 11 upwards to be taught about rape and sexual consent as part of PSHE in schools.

“This would include discussion around what they have learnt from watching pornography.

“Across society, we need to remove the embarrassment and shame that exists around talking about porn – which is why we have launched a ChildLine campaign to help young people to make more informed choices.”

According to the Daily Mail, a similar report by ChildWise in 2013/14 found that Pornhub was one of the top five most popular sites for boys aged 11 to 16.