A report by the Howard League for Penal Reform highlighted overcrowding at HMP Isle of Wight, including Camp Hill (above), which is now closed.
HUNDREDS of prisoners were kept in overcrowded cells on the Isle of Wight last year, new figures reveal.
New research by the Howard League for Penal Reform show that, during the financial year 2012-13, more than 400 prisoners on average were forced to share a cell designed for one person.
At the now closed Camp Hill prison, 254 prisoners shared a cell designed for one while the figure was 141 at Parkhurst and 11 at Albany.
The charity said the statistics — obtained through a Freedom of Information request — came less than a week after a report showed prison staff numbers had fallen by 17 per cent over the last four years.
Nationally, almost 20,000 prisoners were kept in overcrowded cells last year.
The charity said the true scale of prison overcrowding was far greater than government ministers had suggested.
The worst affected prison was Wandsworth, where on a typical day 835 prisoners were forced to share cells which contain an open toilet.
Frances Cook, chief executive of the Howard League for Penal Reform, said: "At last, we have the picture of the real state of overcrowding in our prisons. It’s far worse than anyone imagined: one in four people behind bars are packed like sardines into cramped cells.
"It should come as little surprise that such crowded conditions leave staff hugely overstretched, especially as more are being laid off. This means there are little to no opportunities for prisoners to work, learn or take courses to turn them away from crime.
"Staff cuts and overcrowding mean that grown men spend all weekend and up to 22 hours a day during the week cooped up like battery chickens – no wonder violence and self-injury is rife."