FACEBOOK is encouraging UK users to send the social network their naked photos as part of a new tool that will block the images from being shared online.

As part of a trial scheme designed to tackle revenge porn, the social media giant is working with the UK Revenge Porn Helpline and other rights groups around the world to trial the new tool in the UK, US, Canada and Australia.

Facebook says users can upload any "intimate image" they fear could be made public and it will create a unique fingerprint of the photo, before deleting it from its servers.

The fingerprint will enable Facebook to identify the image without keeping a copy of it should anyone try to upload it to Facebook, Messenger or Instagram - and block it from being posted.

The social network's head of safety Antigone Davis said: "It's demeaning and devastating when someone's intimate images are shared without their permission, and we want to do everything we can to help victims of this abuse.

"We're now partnering with safety organisations on a way for people to securely submit photos they fear will be shared without their consent, so we can block them from being uploaded to Facebook, Instagram and Messenger.

"This pilot programme, starting in Australia, Canada, the UK and US, expands on existing tools for people to report this content to us if it's already been shared."

Facebook said any user who fears images of themselves could be shared online can contact the Revenge Porn Helpline and submit an online form before being sent a secure, one-time upload link for the images in question.

This report will then be reviewed by one of the social network's handful of "specifically trained members of our Community Operations Safety Team", who will create the digital fingerprint which will help keep that image off Facebook's services.

"This is one step to help people who fear an intimate image will be shared without their consent," Ms Davis said.

"We look forward to learning from this pilot and further improving our tools for people in devastating situations like these."

But privacy campaigners have expressed concerns over the pilot.

Silkie Carlo, director of Big Brother Watch said: "Facebook asking women to send nude photos is dangerous and deranged. It's a global intelligence database that has proved it can't protect people's data.

"Its business model is data exploitation, built on sharing users' information with private companies and governments.

"The question is not only whether Facebook can be trusted with naked photos, but whether it can be trusted with personal data at all."