A prison has come under fire after it was discovered to be holding a female inmate in segregation in a "squalid" cell for more than five years.
Shockingly, the discovery was only made because of an unannounced visit to HMP Bronzefield women's prison near Ashford, Surrey, in April, the chief inspector of prisons, Nick Hardwick said.
In the inspection report, Mr Hardwick said: "We were dismayed that the woman who had already been in the segregation unit for three years in 2010 was still there in 2013.
"Her cell was unkempt and squalid and she seldom left it."
Now, the disturbing treatment has been likened to "torture."
Frances Crook, chief executive of the Howard League for Penal Reform, said ministers ought to be left ashamed by the woman's treatment.
"This shocking case of treatment, which appears to amount to torture, in an English prison should shame ministers who tolerate the over-use of custody for women and consequent poor treatment," she said.
In the report, Mr Hardwick added that the woman's "prolonged location on the segregation unit amounted to cruel, inhumane and degrading treatment - and we use these words advisedly."
The prison currently holds 446 women on remand or serving sentences – some of whom have severe personality disorders.
The report stated the treatment and conditions of other women held for long periods in segregation was "little better."
Juliet Lyon, director of the Prison Reform Trust, acknowledged the report showed staff were "doing their best," but branded the sub-standard conditions as "inhumane."
She asked: "Why in this day and age are women with such complex needs transported like cattle and dumped in prison, where one of the most damaged women is left to rot in some form of solitary confinement for five years?"
"We are quick to condemn cruel, inhumane and degrading treatment of people in prison in other countries, now government must act to put right failings in our own women's justice system."
The report has called for a policy to help manage women "with complex needs who cannot be supported in the prison's normal location".
This should include providing a humane and properly resourced environment and regime for those women, as well as for restricted status women in this category, it said.