Paedophiles are being treated with medication as part of a groundbreaking study to see whether it can prevent them from abusing children.

In the first scientific trial of its kind, men who are having sexual fantasies about children are being given a drug normally used to treat prostate cancer.

The drug, called degarelix, dramatically lowers levels of the male sex hormone testosterone, roughly to those of a prepubescent boy.

Sky News was given exclusive access to the trial at the Karolinska Institute in Stockholm, Sweden.

Paedophiles are being treated with medication as part of a groundbreaking study to see whether it can prevent them from abusing children.

The drug being used is normally given to prostate cancer patients

Lead researcher Dr Christoffer Rahm said the drug had been shown to reduce sex drive in cancer patients, raising hopes that it could also reduce the risk of paedophiles sexually abusing children.

He said: “What is considered to be a negative side effect when you use the drug for advanced prostate cancer – reduced sexual arousal – is the effect we want to have in this context (treating paedophilia).”

The researchers will give a single injection of degarelix to 60 paedophiles who volunteer to join the study. None of the men have sexually abused children.

They will be compared with an equal number of men given dummy placebo injections.

Neither the men nor the doctors will know who is getting active medication and it is the first time a rigorous scientific trial has been done on paedophilia treatment.

Past attempts at chemical castration have been anecdotal and inconclusive.

But degarelix is a newer drug that has an immediate testosterone-lowering effect.

Dr Rahm said: “It’s important we have evidence-based treatment.

“We need to shift the focus away from what to do when the damage is already done on to preventing the sexual abuse happening in the first place.”

Sky News met one young man involved in the study. We agreed to protect his identity and gave him a fake name.

‘Anders’ has not abused children, but fears he might.

He told Sky News: “We didn’t choose to be this way. Nobody would, obviously. And yet nobody accepts us, everybody hates us, we can’t be open with it.

“Hopefully (the drug) will take my mind off these things so I don’t have to be so frustrated and miserable.”

All the men in the study will have a series of MRI brain scans taken while they look at computer-generated images.

Anders’ brain scan shows more activity in areas involved in visual processing and arousal when he sees images of children.

The researchers hope to identify a typical ‘brain pattern’ of a paedophile and that treatment will normalise the scan results.

They are also putting the men through psychological tests to see whether lowering testosterone levels works.

They are appealing for £38,000 in public donations on the crowdfunding site ‪Walacea to carry out the study.‬

Sweden has a national helpline called PrevenTell that encourages men with ‘unwanted sexuality’ to come forward.

Men can be referred for psychological interventions and treatment with anti-depressants.

But if the new study is a success they will also be offered testosterone-lowering treatment.

The doctors say 5% of the adult population has sexual fantasies involving children and new ways are urgently needed to prevent them from becoming child abusers.

But it is controversial.

Peter Saunders, founder of the National Assocation for People Abused in Childhood, said: “The abuse of children is not always about a sexual urge.

“We need to look at the whole person, not just one part of their anatomy. It may not solve that person’s dangerous inclination.”