Experts warn of rise in internet blackmail as police probe suicide of Daniel Perry

He was communicating with an American girl, who he believed to be the same age as him, using the video chat service Skype

Daniel Perry: it is believed his blackmailers found his Skype address through social media sites

Charities and internet security experts warned of the growing danger of cyber blackmail today in the wake of the suicide of another teenager who was being harassed on-line.

Daniel Perry killed himself after he was threatened that webcam chats he believed he was having with an American girl would be played to his family and friends unless he paid money into a bank account.

It is believed his blackmailers found his Skype address through social media sites he used. It was reported that he had also been urged to commit suicide on the social network site Ask.fm which has been linked to five other deaths including that of Hannah Smith, 14, whose funeral was held today.

Police Scotland said it was investigating the death of the 17-year-old trainee mechanic from Dunfermline in Fife last month.

Meanwhile, child protection experts urged young people never to give away their real identity, images of themselves or to engage in chat with anyone they had met on-line or through an on-line third party.

Whilst less common than on-line bullying, on-line blackmail is a new and increasingly frequent international phenomenon. Alberic Guigou of the internet company Reputation Squad said he dealt with up to 10 cases a day in France.

"People find you on Skype, social media networks, and they try to trap you into giving away your personal information, especially pictures and videos of you naked.

"Most of the [perpetrators] are professional scammers ... they make it an actual business. But sometimes it is people who go to school with you or people from work - but there is much less of that," he said.

Jim Gamble, the former head of Child Exploitation & Online Protection Centre, who now runs his own on-line safety company INEQE said the threat of being exposed for private sexual behaviour massively increased the power that tormenters' threats had over vulnerable young people.

"Bullying has always existed. It has always been there but at the end of the day this is a wake-up call for us. We need to get a grip here now. We need to do something radical so there are real consequences for virtual bullying. It means applying the laws that currently exist and an appetite to investigate," he said.

"We should not assume that because this is based on an online platform that we can't catch them. They could be in this country - they could know the person they are bullying in the real world," he added.

This week two teenagers appeared in court in Halifax, Canada, accused of the internet bullying of 17-year-old Rehtaeh Parsons. She killed herself after an image of her allegedly being raped by four boys was circulated on-line.

Elaine Chalmers, area manager for the NSPCC's helpline in Scotland, said effort still had to go into educating parents and children of the threat.

"If you've only seen a static picture of someone online, they may not be who they say they are. It's important not to send people pictures of yourself or take part in video calls if you aren't sure who you are speaking to.

"If you have been deceived online, you need to remember that you aren't to blame and you are not the only person that this has happened to," she said.

For confidential support about issues involving suicide call the Samaritans in the UK on 08457 90 90 90 or visit a local Samaritans branch.