The government has scaled back a major IT programme after costs spiralled out of control.
The C-Nomis system is designed to enable the management of offenders from arrest through to sentence, and was originally meant to be rolled out to the prison and probation services at a cost of £234m.
But in a statement the National Association of Probation Officers estimated that the full national roll-out would now cost £950m.
Under the project, more than 200 prison and probation service databases would have been merged to create single profiles on each offender. The aim was to allow prison and probation staff to share information in real-time and manage each case.
The roll-out to the probation service has now been abandoned, and probation officers will have read-only access to the files once the system is installed throughout the prison service.
Prisons minister, David Hanson, told MPs this week that a revised timetable for the roll out will be published in the spring. Three prisons are already using the system.
Harry Fletcher, assistant general secretary of Napo, said, "The whole C-Nomis project appears to have been badly managed since its inception. It is arguably an outrageous waste of public money. As a consequence of the problems probation staff will now have to use systems that are not fit for purpose."