TBC report said Police suspected he was drinking alcohol while he disappeared from the prison.
Police said he was found in a bush area in Loupata not far from the prison compound.
His injury put his life in a critical condition and is currently receiving medical treatment in hospital, Police said.
They said the prisoner was reported missing after a head count of all inmates at Sianai prison at around 5pm.
The details of the man and what he wore at the time he went missing was not released but anyone who saw him is asked to contact police.