Somnath Chatterjee, former Lok Sabha speaker, died at 8:15 on Monday morning in Kolkata, say reports. Chatterjee was 89 years old.
The Times of India reported that he was admitted to Kolkata's Belle Vue Hospital because of a kidney ailment and that a team of 12 doctors was keeping him under close watch.
The report said that he suffered a massive heart attack on Monday morning.
He had been in and out of the hospital for the past two months.
Condolences poured in as the news of his death was announced.
Chatterjee was a member of the CPI(M) most of his life and served as the speaker of the Lok Sabha between 2004 and 2009 when UPA was in power.
He was elected to the Lok Sabha for the first time as an MP in 1971 and was re-elected nine more times.
Chatterjee had joined CPI(M) in 1968.