The panel also said that a CID official tried to kidnap Mr Sheikh in Pakistan a day before Sarabjit's death, when he had accompanied his family to Wagah border to see them off.
Sarabjit Singh, 49, was a death row convict at the Kot Lakhpat Jail in Lahore, Pakistan. On Friday last, a group of other prisoners had hit him on his head with bricks. He was taken to the Jinnah hospital in Lahore in a comatose state and was on ventilator support till he died early on Thursday.
Sarabjit's body was brought back to India on Thursday and he was cremated yesterday in Bhikhiwind, his ancestral village in Punjab.
Doctors who conducted an autopsy on his body near Amritsar said that the injuries showed it was a planned attack, by two or more men and aimed at killing him. Pakistan has described the incident as a scuffle.
The doctors in Amritsar said that Sarabjit seemed to have died of head injuries within 24 hours of the murderous assault and that they now want to see the report of an autopsy that was conducted at the Lahore hospital where he died.
That report is also expected to explain why several of Sarabjit Singh's organs are missing. These organs - his heart, gall bladder and kidneys - might have been removed as part of the first autopsy for testing, said Dr HS Rai, Head of the Forensic Science Department at the Government Medical College and Hospital in Amritsar.
Sarabjit was sentenced to death for bomb blasts in the Punjab province that killed 14 people in 1990. His family says he was innocent and that he had strayed across the border into Pakistan when drunk.