Around one hundred child sex offenders have undergone chemical castration under a government programme to reduce the likelihood of them reoffending.
The paedophiles volunteered for a course of drugs designed to reduce their testosterone levels to that of a prepubescent boy in order to curb their libido.
The treatment is being piloted by psychiatrists at HMP Whatton, Nottingham, a specialist category C prison which holds male sex offenders.
The drug, leuprorelin, which is marketed as Prostap, inhibits the production of testosterone, which is linked to the high sex drives in paedophiles.
The programme is run by the Prison Service and the Department of Health and has been co-ordinated by criminal psychiatrist Professor Don Grubin.
He said: "I have referred around 100 people for treatment. It is still ongoing but I do not have anything to do with the treatment. They come to me in the first instance to see whether the treatment is appropriate for them. ...read more