The government is spending £20,000 a month to provide services for Reading Prison, despite it standing empty.
The jail closed in November as part of plans to replace four prisons with a super-prison.
However in response to a Freedom Of Information request by the BBC, the Ministry of Justice has revealed it is still paying for electricity, gas and security for the site.
It remains unclear what the future of the Grade II-listed building is.
The prison, which was immortalised in Oscar Wilde's poem, The Ballad Of Reading Gaol, closed after 169 years.
However, the site is not yet up for sale.
Glyn Travis, from the Prison Officers Association, said: "The closure programme of prisons by the Ministry of Justice, on the direction of the NOMS management board, was ill thought out, had resulted in significant cost the taxpayer and disrupted the lives of hundreds of prison staff, and their families.
He also said it will have had a "significant impact" on the local community and added the government "paid no foresight into looking at this and approving the closure".
A spokeswoman from the Ministry of Justice said: "We are determined to drive down the cost of running our prisons.
"We will work closely with a number of organisations, including the local planning authority and English Heritage, to ensure that the heritage of former prisons is properly recognised and protected, when considering the future use of any site."