Rizwan of Saibaba Colony in the city was arrested in 1997 on charges of murder of a teacher and was sentenced to undergo life imprisonment.
Suffering from epilepsy for the last two decades, he had come out on parole some two months ago and got married, police sources said.
Police said Rizwan had an epileptic attack last night and fell unconscious this morning and immediately rushed to the Government hospital, where he was declared brought dead, they said.
As the body was lying for postmortem, relatives refused to receive the body, blaming lack of facilities in the prison as the cause of the death.