Controversial Nihang sect chief Ajit Singh Phoola was taken to the civil hospital in Amritsar on Thursday after he was set on fire by some fellow prisoners inside the Amritsar central jail, the police said.
Phoola was admitted to the hospital with over 40 per cent burns, police officials said.
A large number of his supporters from the Tarna Dal, a Nihang (warrior) Sikh sect, gathered at the hospital on coming to know about the incident.
Police sources told IANS that the incident occurred inside one of the prison cells on Thursday morning when Phoola had an altercation with two fellow prisoners.
The police and jail officials are trying to ascertain how the fellow prisoners set him on fire.
Phoola has been a controversial man. He has faced charges of murder and rioting and has been convicted in some cases.
He was used by the Punjab police officials as an informer during terrorism days in Punjab (1981-95) and used to have armed private bodyguards of fellow Nihangs besides police personnel for his security.