Bittu was beaten to death by rods in the high-security Nabha prison, near Patiala, by a murder convict and a murder accused on Saturday evening. He was taken to the Civil Hospital where doctors declared him dead, police said.
"We raised our demands with government representatives. Our main demand is to drop all false charges framed against my father," Bittu's son Arminder Kumar told reporters in his hometown Kotkapura in Faridkot district.
"He is no more in this universe. At least now the stigma labelled against him should be dropped. We will not cremate him until he is freed from this stigma," he added.
Bittu, who wanted in many cases including inciting violence in Haryana's Panchkula town after the conviction of Ram Rahim Singh in 2017, was arrested by a special investigation team from Himachal Pradesh's Palampur town last year.
He was considered to be close to Dera Sacha Sauda sect chief Gurmeet Ram Rahim Singh, who is serving a life sentence for the murder of a journalist, as well as a 20-year sentence for raping two female disciples.
A 45-member executive committee of Dera Sacha Sauda, which has been camping here, is demanding a judicial probe into the killing of Bittu.
"The body will not be cremated until our two demands are accepted by the government. The first is a judicial probe into the killing and the second is dropping of all criminal charges against all Dera 'premis' (followers)," committee member Harcharan Singh said.
Preliminary investigations said Bittu was allegedly killed by murder convict Gursewak Singh and Maninder Singh, an under-trial in a murder case, with iron rods removed from a barricade.
Inspector General, Patiala range, A.S. Rai said both the attackers are baptised Sikhs. "They say they attacked Bittu because he is the main accused in the Bargari case."
Following the incident on Saturday, Chief Minister Amarinder Singh had ordered an inquiry into the fatal assault on Bittu.
Additional Director General, Prisons, Rohit Chaudhary will head the fact-finding committee, which has been asked to submit a report within three days.
Amarinder Singh had ordered beefing up of security in the state in the wake of the attack, while appealing to all communities to maintain peace and not give into rumours.
The sacrilege case relates to the alleged desecration of the Guru Granth Sahib in Bargari village in Faridkot in October 2015.
Following the crime, two people were killed and many others injured in Behbal Kalan village of the district on October 15, 2015, in police firing on protesters.
( With inputs from IANS )