There is “much room for improvement” at a Sussex prison which suffered £5m worth of damage during 12 hours of riots, an independent report has said.

An Independent Monitoring Board report into Ford Open Prison, which was torched by inmates on New Year’s Day 2011 after staff lost control, has said it was “very concerned” about staffing levels. The newly-released report said there was 150 staff working at the prison in October 2013, down from 160 the year before.

The report said this was largely down to “cost-cutting” but added staff had suffered from stress and sickness.

The monitoring report said: “The board is very concerned that the level of reduction in staff is likely to have a serious effect on the efficient running of the prison.

“The constant pressure under which staff are now expected to work leads to increased levels of sickness which in turn places even more pressure on those who report for duty.

“Frequently, staff have to be taken off normal duty to cover for those who are not available.

“While the board does not consider the stability of the prison to be compromised, it remains concerned at staffing levels at night and also in reception where the board believes more security checks should be carried out.”

Recently Ford has also been in the news because prisoners – including murderers – have absconded while on day release.

The report said: “This is common to the open estate and not particular to Ford. As a result, since the reporting date, no new offenders are allowed to be transferred to open prisons unless the sending prison has completed an Offender Assessment (OASys) report on them.

"This was always supposed to be done but often wasn’t and in practice it was difficult to send offenders back due to lack of capacity in the closed prisons and the cost to Ford of returning them.”

It also said drugs remained a problem at Ford, adding it “regretted” that sniffer dogs were not used.

A Prison Service spokeswoman said: "Concerns around staffing levels have been addressed with prisoner officer levels adjusted to match the operational needs of the establishment.

"Sickness absence levels at HMP Ford are significantly lower than for the same period last year, and night staffing levels have since been increased.

"This report will now be considered fully by ministers, who will respond in due course."