Kumar, who was serving a life sentence, was rushed to Safdarjung Hospital, where doctors declared him brought dead.
The cause of his death has not yet been clarified.
Who was Sajjan Kumar?
Kumar, a former Congress MP from Delhi, was among the prominent political figures prosecuted in connection with the 1984 anti-Sikh riots, which followed the assassination of Prime Minister Indira Gandhi by her Sikh bodyguards on October 31, 1984.
Kumar was initially acquitted in several cases, but his legal fortunes changed decades later.
2018 conviction
In December 2018, the Delhi High Court convicted Kumar and sentenced him to life imprisonment for his role in the killings of five members of a Sikh family in Delhi's Raj Nagar area and the burning of a gurdwara.
He remained in custody following the conviction.
Another life sentence in 2025
In February 2025, a Delhi court sentenced Kumar to another life term for the murders of Jaswant Singh and his son Tarundeep Singh during the riots in the Saraswati Vihar area.
The court found him guilty of instigating and participating in the attack.
Acquitted in another case
Kumar had also received acquittals in other cases linked to the 1984 riots.
In January 2026, a Delhi court acquitted him in a case concerning alleged violence in Janakpuri and Vikaspuri. He continued serving his life sentence from his earlier conviction.