He also said the family will take Singh's body to Karauli village in Rajasthan where the last rites will be held.
"My brother was murdered. I have seen injury marks on the body and finger marks on the throat," the brother, who did not wish to be identified, said.
Meanwhile, the post mortem of Singh's body was conducted at AIIMS here today.
Singh was found hanging in his cell in Tihar Jail at around 5:30 AM yesterday and the body was brought to AIIMS at around last evening after completion of various proceedings.