Khekiho Zhimomi, Nagaland's lone Rajya Sabha MP, died here on Thursday, leading to the adjournment of the upper house for the day.
The Nagaland People's Front (NPF) leader was admitted to the All India Institute of Medical Sciences three days ago due to "severe heart issues", one of his daughters told IANS.
"His health deteriorated and he died today (Thursday) morning at 6," she said. The family said his body would be taken to Nagaland after autopsy.
The Rajya Sabha was adjourned after an obituary reference to Zhimomi, who Chairman M. Hamid Ansari described as an "active social worker who strived for the upliftment of weaker and downtrodden sections of society".
He was a member of the Rajya Sabha twice, from July 2008 to April 2010 and from April 2010 till his demise.
Zhimomi had recently visited Myanmar with National Security Advisor Ajit Doval for the signing of a peace pact between several insurgent groups and the Myanmar government.