Why Qld jails are bungling releases

Why corrections need to be made in Queensland's corrective services:

* The Queensland Audit Office has found 329 prisoners have been freed on the wrong release date in the past 11 years

* Their review found 238 prisoners were kept too long, while 91 were incorrectly released early

* One was freed 963 days ahead of time (but was returned 35 days later), while the average of those released early was 51 days.

* The actual number of cases of late releases may be much higher as only the cases where prisoners made a complaint are recorded

* One prisoner was released one full year early but re-arrested 18 days later for breaching his DVO

* Nearly three-quarters of the errors were due to communication issues between the various corrections departments, with bad data entry and incorrectly calculating a prisoner's sentence also identified.