Paedophiles are targeting Premier League youth players on Snapchat by posing as football agents and scouts in a bid to groom and entrap them.

Adam Green, head of safeguarding at Everton, said that last season young players at the club revealed they had been approached through the messaging app by men who claimed they wanted to sign or represent them.

The disclosures came when the club ran a project with the Internet Watch Foundation (IWF), a charity that works to eliminate child sexual abuse. The project aims to teach young players about the dangers they face online and how to conduct themselves appropriately.

Green said this method of online grooming was “very prevalent” and he had heard of other cases across the country. “On Snapchat it just says a name like Ben at the top and [the message says]: ‘I’m from an agency representing players from Manchester and London, and we have offices in both places and we’ve been watching you with interest, following you, and we’re interested in signing you for this agency. Don’t tell your dad. Don’t tell your club.’”

Concerns about Snapchat messages were first raised by two younger boys. When Green mentioned the cases to 17 and 18-year-old players in one of the IWF training sessions they showed him dozens of similar messages.

He said gangs were also trying to blackmail young footballers via sexting. “There have been cases coming to court of academy footballers from all different clubs [being] told that they had to pay £50,000 if they don’t want their penis pictures sent all over the internet.”

The warning comes after several high-profile players have fallen victim to a scam known as “catfishing” where they are duped into interacting intimately with women or men via webcams. In April it was reported that a video of the former England goalkeeper David James performing a sex act during a Skype call had been leaked online.

Andy Wood, leader of the IWF project, said: “That video’s now on lots of gay porn sites. You don’t know who the people on the other end of the webcam are.”

Green said the number of young players reporting concerns to the club about sexual and threatening online behaviour has grown exponentially in recent years. Everton’s safeguarding team received 126 statements of concern last year, including issues such as “sextortion”, online bullying and familial abuse, from academy players, pupils at the club’s free school and charity, and community groups – up from 75 in the previous year. This compared with three referrals when he joined the club 11 years ago.

Green said: “The threat now is that paedophiles have migrated … to Instagram and Snapchat. Whatever the next craze is, the paedophiles will be on there as soon as the children are.”

The IWF project not only educated young players about the dangers of online abuse but also aimed to prevent them from acting inappropriately online, following the conviction of Adam Johnson, the former Sunderland and England footballer jailed for grooming and having sexual activity with a girl aged 15.

Last season the pilot project ran 26 training sessions for young men aged 16-24, including sessions on sexting, revenge porn and consent by a partner, the impact of pornography on sexual behaviour, and how to report online images of child sexual abuse. The training will continue next season.

Green said one of the biggest changes they saw during the workshops was on attitudes towards consent. “I think one of the reasons why it changed behaviours was that those who saw girls who were drunk as fair game were really challenged by their peers. [They were asked,] ‘So if you were blind drunk and a girl – or a boy – touched you in a way that you’re describing, would you see yourself as fair game?’”

One academy player who underwent the training said: “There’s a lot of responsibility on us. If we want to be professional footballers we’ve got to embrace that.”

Another said the training made him aware of the added risks they faced at a Premier League club. “It made me realise we’re much more of a target – more than other lads our age.”

[The academy players spoke on condition of anonymity.]

Green added: “For the elite players there’s an additional element … everyone knows they’re the Everton player and girls will target them more so – and predatory paedophiles and predatory people who want to make a profit out of it with sextortion.

“If one of our young men goes on a dating site or even to a nightclub, word gets around pretty quickly that they’re a footballer and it’s much more tempting to start some kind of grooming relationship or befriend them, or try to have sex with them and ultimately have their baby. ”

Susie Hargreaves, chief executive of the IWF, said the motivation for partnering with Everton was that young men were the most likely group to come across child sexual abuse images online while using mainstream porn sites but were the least likely to report them.

She said the foundation had asked the Premier League to join the project’s advisory board but it had declined, although a monitor was sent to one of the training sessions. “It’s been really disappointing to us that the Premier League didn’t get involved in the project.”

The charity also approached Liverpool, Manchester United and Manchester City but they declined to take part in the project. Liverpool said it already had a training programme that used experts in the field.

Hargreaves added: “The Premier League clubs have a duty to provide safeguarding and their safeguarding teams vary in size. Some of them are tiny.

“It needs to be taken on board at the highest level.”

Nicola Marsh, head of social and political research at ComRes, said the evaluation suggested that the project had led to a significant improvement in the understanding of online sexual abuse by the participants at Everton, particularly on consent, blackmail and reporting child abuse images.