The scale of sex crimes against children is much bigger than anybody imagined with apps like Snapchat enabling paedophiles to pinpoint the location of potential targets, according to a police boss.

North Wales Police and Crime Commissioner Arfon Jones is horrified the popular photo messaging app has a mapping device which shows exactly where the child is unless the privacy settings are switched on.

Mr Jones was speaking after a visit to the Onyx team that was set up by North Wales Police in 2015 to combat child sexual exploitation in all its forms.

He called on parents to be more vigilant and to keep tabs on what their children were up to online, as well as ensuring their privacy settings were in “ghost” mode so that predatory perverts could not find out where they were.

The plea from the police commissioner comes on the heels of news that Chrissy Teigen, the host of hit TV show, Lip Sync Battle, has quit Snapchat.

Earlier this year £1 billion was wiped off Shapchat’s share price after American reality television personality Kylie Jenner tweeted to her 24.5 million followers she was abandoning the app.

According to Mr Jones, tackling child sexual exploitation is one of the main priorities in his Police and Crime Plan which sets out the overall strategy for policing North Wales.

The commissioner pledged to back the team with the resources it needs to protect children from being snared online.

He said: “There is nothing more important than keeping children safe and it is vitally important we educate children about the dangers lurking online and how to avoid them.

“At the same time, parents also need to be aware what their children and doing on social media and making sure privacy settings are always switched on.

“Social media companies also have a responsibility about how their apps are used, taking down any inappropriate images and closing down accounts.

“But the only way to stop this happening in the long run is to educate children and parents and not sharing images with people the don’t know.”

Detective Sergeant Sarah Fellows, who heads up the Onyx team, revealed they are currently managing 7 9 children across North Wales who are at risk of child sexual exploitation.

She said: “Our role is to to improve the early identification of children who could be at risk of child sexual exploitation and work with our partners to put in place timely and effective intervention and disruption.

“We also work to identify suspects who could who could be perpetrators early as we can really, to disrupt, to investigate, and if possible bring about prosecutions.

“Our work is not only about the investigation of offences. We look at the children themselves and what’s going on in their lives to identify those that possibly could be at risk. We then work with other agencies to safeguard them.

“That might involve prosecutions, social services doing work with the children or engaging them in different activities.

“All parents need to be looking at their children’s devices and see what they’re using and what their settings are.

“For instance Snapchat now has got the mapping on it whereby you can see exactly where that child is. So unless you’ve got the ghost mode turned on, everybody who is on that Snapchat with that child will know how to pinpoint where they are.

“It can escalate very quickly, just engaging in conversation, and perpetrators will be asking leading questions very early, testing the water to see how far they think they can go.

“Then as soon as they think a child is engaging in that conversation they will maybe be asked for an exchange of images or asked to meet.

“Sometimes they may just be innocent images to start with, and then pushing the boundaries.

“We would ask if anyone has any concerns about a child they know, or information which may be useful please contact North Wales Police.”

Mr Jones, a former police inspector, added the work of the Onyx team had revealed the scale of child sexual exploitation was greater than anybody knew.

He said: “The emergence of complex crimes like this is one of the main changes I have seen since I was in the job.

“People say that if we don’t arrest offenders, charge and convict them that we’ve failed.

“I don’t agree with that because if you safeguard the victim that is a result in itself, it’s not always a matter of getting people to court.

“I think we have to have different measures of success where education and raising awareness has a prominent role to play.

“It’s always going to be far better if we can prevent a child being harmed in the first place.”