A review of staffing levels at Ford open prison will be held following riots there over the new year holiday, the prisons minister has said.
Crispin Blunt also said those involved in the riot at the open prison in West Sussex "must be brought to justice".
When the riots broke out, there were two prison officers and four support staff on duty.
Mr Blunt visited the site on Sunday and said he expected a police investigation as well as a Prison Service inquiry.
A number of buildings were burned to the ground during the riots, which is thought to have begun after prison staff attempted to breathalyse some inmates.
Mr Blunt also responded to concerns raised by Mark Freeman from the Prison Officers' Association and others that the prison was understaffed.
The minister told the Press Association (PA) news agency: "One of the issues will be about whether there are particular circumstances at Ford - to examine whether the staffing policies are appropriate at Ford compared to other open prisons."
He revealed the team had minimum staffing on the night after one support officer, who called in sick at short notice, was not replaced - but said when the shifts changed, there had been "no indication or intelligence that anything untowards was happening".
Mr Blunt also said staff, governors and inmates were "appalled and disgusted" by the riot, and the situation had been "unprecedented in an open prison".
He said a police inquiry could lead to criminal prosecutions, and added: "We must learn the lessons to make sure it does not recur."
The Prison Service inquiry is to be led by the regional custody manager for Wales.
Michael Spurr, from the National Offender Management Service, which is responsible for managing the Prison Service, said staffing levels at the time were "appropriate and usual".
He added: "These types of incidents in open prisons are rare and it is to the credit of all the staff involved that no staff or prisoners sustained significant injuries during the incident."
But a former inmate, Dave, told BBC Radio 5 live that staffing was a problem at the prison.
He said: "Certain inmates in there they will be encouraged to jump over the fence, nip down to Tesco's, which is just down the road, and go and get x amount of pounds of alcohol.
"That's reality. If they had more staff in there it wouldn't happen."
Her report said that "the size of the site and low staffing level at night meant that it was relatively easy for prisoners to leave residential areas at night and return with alcohol and other contraband purchased locally or left on the edge of the perimeter by accomplices".
It recommended that there should be increased patrolling of residential areas at night.
Lord Brocket served time at HMP Ford after being jailed for fraud in 1996.
He told the BBC that the issue of staffing levels at the prison were a "complete red herring".
He added: "If you beef up the staff you then make it a much more secure prison, a bit like category C prisons, which is where a lot of them have come from. You want to keep it as an open prison, they always have had low staffing levels."
Lord Brocket said that if prisoners wanted to riot then "trust me, there's still going to be a riot, even with a hundred wardens there".
The Prison Officers' Association said the incident started around midnight on New Year's Eve after staff tried to breathalyse some prisoners.
It was about another 22 hours before the disturbance was "successfully resolved" by specially trained staff, according to the Prison Service.
About 40 inmates out of the 496 on the site were involved in the riot, and the fires destroyed six accommodation blocks, a mail room, a gym, a snooker room, and a pool room.
The Prison Service had feared it would have to move 150 prisoners to closed conditions either because they were involved in the disturbances or because of damage to their accommodation, but as of Sunday, the figure stood at 23.
HMP Ford accepts category D offenders who have under two years left to serve on their sentences.
They are given opportunities to work and are helped to resettle. Inmates have more freedom than those in closed prisons.
The Prison Service website says the institution does not house criminals who have been convicted of arson, some sexual offences, or "restraining" offences.
The facility is split into two sites divided by a main road. One of the sides is mainly residential, while the other generally consists of work spaces.