The 10-minute film, Exposed, has been developed by the Child Exploitation and Online Protection Centre in response to the increasing popularity of sexting among teenagers.

The film is aimed at 11 to 16-year-olds and encourages them to think about their actions and how their lives may be affected in the future.

CEOP said young people often did not realise that the images they share of themselves digitally may end up in the hands of others, including in some extreme cases the collections of child sex offenders.

Peter Davies, chief executive of CEOP, said it was important that young people make the right choices.

“We know that young people are increasingly using technology not only to stay in touch, but to explore their sexuality and to push the boundaries in what they send and to whom they send it,” he said.

“It is now so easy to send pictures instantly via emails and texts that we are seeing instances of boys or girls sending sexual images of themselves to others without considering the consequences.

“They often find out later that the image has been passed on to many others and as a result they can be the victims of bullying or harassment.”

Minister for Crime Prevention, James Brokenshire, said that sexting was a “worrying trend”.

“We should encourage young people to use technology but it’s really important that they are made aware of the dangers involved too,” he said.

The film is available at www.thinkuknow.co.uk/teachers