Compensation payments made to inmates have almost doubled in the past year to more than £4m, official figures show.
Prisons have been warned not to give into compensation culture
The Home Office has confirmed this included a claim for £2.7m by one prisoner but they would not confirm it stemmed from a failed suicide bid.
Government statistics showed most other payments were made out-of-court for claims relating to injuries, assaults and "medical negligence".
A Prison Service spokesman said figures varied "considerably" each year.
Home Office minister Gerry Sutcliffe revealed the figures on Wednesday in answer to a Parliamentary question.
A total of £4,017,233 was paid in compensation by publicly-run prisons in out-of-court settlements in the year 2005-06, while in 2004-05 the figure was £2,160,530.
Figures revealed almost £3.5m were made for "miscellaneous injury" and £113,250 was paid to prisoners after alleged assaults by staff.
A spokesman for the Prison Service said: "Each compensation claim received by the Prison Service is treated on its individual merits.
"It is also important to consider that any high-cost claims that are settled during a given year can completely distort the total amount of compensation that is paid out - making it very difficult to identify any genuine trends or significant year-on-year developments," he added.
Shadow prison minister Edward Garnier warned jails not to give into the "compensation culture".
"Genuine claims should be appropriately dealt with but prisons should make sure they are not succumbing to the compensation culture," he said.
A report in the Times newspaper claimed the £2.7m pay-out to an individual was for an inmate who required long-term medical care because of self-harm committed in jail.
But the Home Office refused to comment on individual cases.
The head of the Prison Service's operational litigation unit, Derek Ramsden, said jails had been affected by the culture of litigation affecting the rest of society.
He told the Times: "Accidents happen, but now people often look for someone to blame rather than themselves.
"Personal injury can cover a multitude of sins: slipping or falling down stairs, a chair collapsing, falling off a ladder or through a ceiling. We even had one prisoner that had his finger bitten off by a horse."