Almost half of 15-year-olds in Suffolk are researching anorexia online and a third are using the Internet to view self-harm sites, according to an annual survey into online safety.

The latest Suffolk cybersurvey, published today, also reveals there has been an eight per cent increase in the number of 15-year-olds 'sexting' – a rise from 11pc in 2016 to 17pc last year.

The results show that 44pc of 15-year-olds are visiting pro-anorexia sites – up 9pc on 2016 – and the number looking at self-harm promoting sites has also jumped 13pc to almost a third of children in the same age bracket.

The survey reveals a clear drop in parental input for children aged 15 and over, which according to the authors, correlates with the increase in risk-taking behaviour.

This is despite the good news that more parents are delivering messages of online safety to their children from a young age – with 62pc of children saying they always listen to parents' advice, up from 57pc in 2016.

Eight in ten are also taught about online safety at school.

Suffolk's police and crime commissioner Tim Passmore said he was 'obviously concerned' about the risks taken by 15-year-olds. But he said he was encouraged by parents' increased involvement in their children's Internet use.

'These trends are deeply worrying,' he said.

'We have got to do what we possibly can to stop this happening – prevention is far better than cure.'

He added that Internet safety should be 'a priority', and Suffolk should aim to teach safe practice to 100pc of children at school.

'In an ideal world every child at school would be taught about online safety, it should be a compulsory part of every child's education,' Mr Passmore said.

Gordon Jones, Suffolk County Council's cabinet member for children's services, education and skills, said of the results: 'I would urge parents and schools to continue to re-enforce messages of online safety with children from a young age and vitally, sustain this support through their teenage years.

'It is also important to keep a close eye on what children are viewing online as well as the length of time they spend.'

The results released today coincide with National Safer Internet Day. To find out more, or to register as a supporter, visit www.saferinternet.org.uk