Indian billionaire investor Rakesh Junjhunwala, dubbed “India’s Warren Buffett” by the Indian media, has died at the age of 62, his office said in a statement.

Indian Prime Minister Narendra Modi called him “indomitable” and expressed regret over his death on Twitter, as did other Indian officials.

The “big bull of Dalal Street” – Wall Street in Mumbai – was worth an estimated $6 billion, according to Reuters, and significant stakes in 30 of India’s largest companies.

He recently invested $35 million in 40% of Akasa Air’s low-cost carriers, which made their first flight today.

“Full of life, full of intelligence and insight, he leaves an indelible legacy in the world of finance,” Prime Minister Modi said.

Junjunwala’s office confirmed to AFP that he died this morning, without giving details.

“Rakeshji left with his family and loved ones around him,” one of the family members told Reuters, using an address showing respect.

The cause of his death has not yet been reported. Indian TV reported that Rakesh Jhunjhunwala was taken to a Mumbai hospital around 6:45 am after suffering a cardiac arrest. Upon arrival at the hospital, he was pronounced dead.