Meghalaya Assembly Speaker Donkupar Roy passed away on Sunday at a hospital in Gurgaon following a brief illness, officials said here.
He was 64.
Roy, the former chief minister of the state, was first admitted to a state-run hospital in Shillong before being referred to the Medanta Hospital in Gurgaon, Haryana, where he was undergoing treatment for the last 10 days, his family members said.
His condition deteriorated after suffering multi-organ failure on Sunday afternoon, they said.
Prime Minister Narendra Modi has expressed anguish over Roy's demise, saying he "transformed many lives".
"Anguished by the demise of Dr Donkupar Roy, Speaker of the Meghalaya Assembly and former CM of the state. Passionate about Meghalaya's progress, he served the state with great diligence and helped transform many lives," the Prime Minister's Office tweeted quoting Modi.
"Deeply saddened by the untimely demise of Speaker of Meghalaya Assembly Dr Donkupar Roy. We have lost a leader, a mentor, who had dedicated his life for the service of the people. May Almighty provide strength to his family in this hour of grief. May his soul RIP," he tweeted.