A record number of paedophiles were chemically castrated in UK prisons last year, The Sun reported on Sunday.
The newspaper reports that the Ministry of Justice has announced that number of offenders referred for treatment more than doubled to 25.
The convicted sex offenders volunteered to undergo chemical castration in the controversial government scheme, which aims to prevent them from reoffending.
The treatment was piloted by psychiatrists at HMP Whatton, Nottingham, a specialist prison which holds 851 male sex offenders. A total of 92 sex offenders were treated during the pilot scheme, which has now been rolled out nationwide.
The prisoners volunteered to take a course of the drug leuprorelin, which is sold as Prostap for treating prostate cancer. This hormone drug reduces the prisoner's testosterone to that of a prepubescent boy, in a bid to reduce their sex drive.
Guidance on administering leuprorelin for chemical castration suggests that it should be used on those with compulsive or impulsive urges to offend, difficulties in controlling sexual arousal, intrusive sexual fantasies or urges, sadism or other "dangerous" tendencies, such as necrophilia.
Chemical castration is mandatory for child sex offenders in several countries including Poland, Macedonia, South Korea, Moldova and Russia. It has also been used in nine US states.
In February, Oklahoma senator Mark Allen proposed legislation that would allow violent sex offenders to secure early release from prison if they voluntarily agreed to be chemically castrated.
The method was also discussed earlier this month in Australia, with New South Wales premier Mike Baird saying he would not rule it out. "My view is we need to do everything possible to deter anyone undertaking this horrendous child abuse," he told the Australian Associated Press.
Chemical castration has previously been tried in Sweden, Denmark and Canada. Evidence from Scandinavia suggests it can cut rates of reoffending from 40% to 5%.