B B Das sustained head injuries when the undertrial prisoner, said to be mentally unstable, allegedly pelted bricks at him from the roof of the jail yesterday evening.
The undertrial had climbed the roof in the failing light in the evening and allegedly attacked the warden when he attempted to catch him, in-charge of Kodala jail A K Rath said.
Das was admitted to the government here and later shifted to a private hospital in Bhubaneswar as his condition worsened, sources said.
The undertrial has been shifted to circle jail, Berhampur and put under treatment.
The undertrial was lodged in the jail in April last year on charge of attempt to murder.