More men are raped in the U.S. than woman, according to figures that include sexual abuse in prisons.
In 2008, it was estimated 216,000 inmates were sexually assaulted while serving time, according to the Department of Justice figures.
That is compared to 90,479 rape cases outside of prison.
The Department for Justice has now begun implementing new regulations to tackle the high rates of rape in federal prisons.
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In recent studies 4.5 per cent of 16 and 17-year-olds in adult prison and 4.7 per cent of those in jail reported being the victims of sexual abuse.
The new Department of Justice rape regulations include separating under 18s from adult prisoners.
However, some critics say that will leave many youngsters in virtual solitary confinement.
The new regulations also include banning male prison staff from doing pat-downs in women’s prisons.
The rule changes have been brought in ten years after Congress passed the Prison Rape Elimination Act.
Under the terms of the act, all detention facilities are required to take a zero-tolerance approach to rape behind bars.
SEXUAL ASSAULT IN PRISON: THE SHOCKING STATISTICS
According to the latest National Inmate Survey, 4 per cent of prisoners, 3.2 per cent of people in jail and 9.5 per cent of those in juvenile detention said they had been the victim of sexual abuse.
Almost seven per cent of women said they had been sexually abused by a fellow inmate, while more men said they had been assaulted by staff.
The National Survey of Youth in Custody found 4.5 per cent of juveniles held in adult prisons had been abused.
Those figures have prompted calls for all under 18s to be detained outside adult prisons.
Of the youngsters held in juvenile detention, 2.5 per cent of boys and girls and said they had been abused by fellow inmates.
Shockingly, more than 7 per cent of teenagers in juvenile detention said they had sexual contact with staff.
- Figures published in the New York Review of Books
Procedures also must be put in place to investigate allegations of sexual assault and improve care for victims.
The report found incidents of women prison staff assaulting male prisoners.
States that do not implement the regulations will lose five per cent of their federal funding for prisons, US News reported.
They have also been warned they could face civil court cases from victims.
Separate figures produced by the Bureau of Justice Statistics found that sexual abuse rates in juvenile detention were as high as 9.5 per cent in 2011 to 2012.
In the same year, four per cent of state and federal prisoners and 3.2 per cent of all people in jail surveyed said they had been a victim.
Study author Allen J. Beck told New York Review of Books that the work shows almost 200,000 were sexually abused in detention in 2011.
He said the figures are lower than those recorded in 2008 because fewer people are in prison.
High rates of abuse were found among gay, lesbian and mentally ill inmates and inmates who had been abused before incarceration.
According to official statistics on rape conviction rates, the U.S. Bureau of Justice said 91 per cent of the victims were women and 99 per cent of the perpetrators were men.
Just 9 per cent of accusations made by men resulted in a conviction.
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