It cost taxpayers more than £100 a day to keep each inmate locked up at Preston prison last year, new figures reveal.
The Prison Reform Trust said rising prisoner costs across England and Wales are a concession to "crumbling prisons being run on the cheap" for many years.
Ministry of Justice data shows the average bill per prisoner at HMP Preston was £40,993 in 2019-20 – the equivalent of £112 per day.
That was up per cent from £40,614 the previous year, and 35 per cent more than the £30,270 cost in 2014-15.
With an average population of 680, it meant Preston prison spent around £28 million keeping inmates behind bars last year.
The figures cover direct costs met by the prison, as well as any cash it is required to spend on centralised admin and management services.
Excluding the latter, the direct cost per prisoner at Preston prison last year was £27,459.
Frances Crook, chief executive of the charity Howard League for Penal Reform, said decades spent funding an "overcrowded and overburdened prison system" have held the country back.
"It is costly to the taxpayer, but more importantly, it has fuelled more crime," she added.
"If we want safer communities, we must take sensible steps to reduce the prison population. Think of what could be achieved if we invested in schools and hospitals instead."
Across England and Wales, the average overall cost per prisoner was £42,700 in 2019-20, an increase of 3.7 per cent on the year before.
Young offender institutions for boys aged 15 to 17 had the highest costs on average, at £144,700, while male open prisons spent the least – £34,800 per inmate.
Alex Hewson, senior policy and communications officer at the Prison Reform Trust, said the increase is an acknowledgement that taxpayers have been "short changed" by crumbling prisons being run cheaply.
He said: "The effects of years of prison budgets being pared back to the bone have been plain for all to see.
"Rather than repeating the same mistakes of the past, we need to invest in more effective support and rehabilitation outside of our prisons to guide people away from crime, helping them – and their communities – to prosper."
A Ministry of Justice spokesperson said: “We’ve invested in our prisons to make them safer and more effective at delivering the rehabilitation that will cut reoffending and crime.”