Colourful stock market billionaire Rakesh Jhunjhunwala — dubbed by local media India's Warren Buffet — has died, his office said on Sunday, just a week after he launched the country's newest airline.

“Rakesh-ji passed away surrounded by his family and close aides,” a family member told Reuters, using a term for respect. The cause of death was not immediately announced.

Calling the 62-year-old “indomitable”, Prime Minister Narendra Modi echoed tributes from other senior officials, tweeting that the death of the tycoon was “saddening.”

“We are deeply saddened,” Akasa Air, which Jhunjhunwala co-founded, said in a statement. “We at Akasa cannot thank Jhunjhunwala enough for being an early believer in us and putting his trust and faith in us to build a world class airline,” .

Uday Kotak, the chief executive of Kotak Mahindra and a friend from school days, said Jhunjhunwala had “believed stock India was undervalued” and that he was right.

“Amazingly sharp in understanding financial markets,” Kotak tweeted. “We spoke regularly, more so during Covid. Will miss you Rakesh!”

The “Big Bull of Dalal Street” — the Wall Street of Mumbai — had a net worth of $3.5 billion with significant holdings in more than 30 Indian blue chip stocks.

Jhunjhunwala's excellent communication skills helped small investors understand the stock market, said businessmen and bankers based in India's financial capital, Mumbai, who had interacted with him for over 30 years. His insights on the economy and companies made him a popular TV celebrity.

Jhunjhunwala's bets include a number of companies run by Tata Group, one of India's largest conglomerates.

These include Tata Motors, watch maker Titan, Tata Communications and Indian Hotels Co, which runs the Taj hotels. Other investments include Indiabulls Housing Finance , Star Health Insurance and Federal Bank

He had invested $35 million for an estimated 40 per cent stake in Akasa Air which made its maiden flight in the Asian country's crowded aviation market last Sunday.

Having made his money betting on stocks and lacking any experience in the airline industry, the decision to enter the capital-intensive sector raised eyebrows.

“A lot of people question why I've started an airline. Rather than answer them, I say I'm prepared for failure,” he told an industry event in February.

“It's better to have tried and failed than not tried at all,” he said. “I hope to prove people wrong. Now it's become a matter of ego.”