JMM founder Shibu Soren died on Monday, his son and Jharkhand Chief Minister Hemant Soren said. He was 81.
Shibu Soren, a former chief minister of the eastern state, was undergoing treatment at Sir Ganga Ram Hospital in Delhi for over a month for kidney-related problems.
"Respected Dishom Guruji has left us all... I have become 'shunya' (zero) today," Hemant Soren posted on X.
Shibu Soren had been regularly receiving treatment at the hospital for an extended period of time.
According to Dr A K Bhalla, chairman of the Nephrology Department of Sir Ganga Ram Hospital, Shibu Soren was declared dead at 8.56 am.
The tribal leader died after a prolonged illness.
"He was suffering from kidney ailments, and had suffered a stroke a month and a half back. He was on life support for the last one month," the doctor said.
"He was admitted here recently, so we came to see him. His health issues are currently being examined," Hemant Soren had said on June 24 when his father was admitted to the hospital in the national capital.
Last week, Hemant Soren had said that Shibu Soren had fought several battles and he would win his health battle too.
Shibu Soren had been the leader of the Jharkhand Mukti Morcha for the past 38 years and is recognised as the party's founding patron.