Sidheshwar Yadav, who was arrested two days ago under Arms Act, was involved in a clash with some jail inmates yesterday in which he suffered internal injuries and died while being taken to Sadar hospital, Superintendent of Police Aditya Kumar said.
Yadav was resident of Deoraj Bigaha village in Jehanabad district.
The body has been sent to Sadar hospital for post-mortem, Kumar said.
The incident sparked off a protest by the local people who blocked NH-83 for over an hour demanding an inquiry into the inmate's death, the SP said.