India's Gautam Adani once again became Asia's richest man on Friday, according to a Bloomberg index of the world's billionaires, a year after allegations of market manipulation hammered his conglomerate's stock prices.

Adani Group saw more than $150 billion wiped from its market value after a bombshell report by US investment research firm Hindenburg Research accusing it of "brazen" corporate fraud. 

The family-run conglomerate's founder, the world's second-richest person ahead of Tesla founder Elon Musk, saw his personal fortune collapse by around $80 billion.

But both Adani and his business have since pared much of those losses as public scrutiny receded.

The Bloomberg Billionaires Index showed Adani's net worth gained around $7.7 billion this week to reach $97.6 billion, narrowly eclipsing fellow Indian tycoon Mukesh Ambani. 

The two men are now respectively the 12th and 13th richest people in the world, according to the measure. 

Shares in listed Adani Group companies jumped this week after India's top court dismissed a petition seeking to widen a probe into the Hindenburg allegations, saying that existing investigations by market regulators were sufficient. 

"The honourable supreme court's judgement shows that: Truth has prevailed," Adani said on X, formerly known as Twitter, after the ruling.

"I am grateful to those who stood by us. Our humble contribution to India's growth story will continue," he added. 

Hindenburg, a short-seller investment house, not only tracks corporate wrongdoing but also makes money by betting on stocks falling.

Adani has denied the allegations of fraud documented in its report, last year calling it a "deliberate attempt" to damage the image of his conglomerate for the benefit of short-sellers. 

Before the report, Adani Group's share prices had risen meteorically with its main listed unit shooting up more than 1,000 percent the five years to January 2023, funding a breakneck expansion of the conglomerate.

Its reach now spans a number of key sectors including coal mining, renewable energy, ports, and airports.  

Adani is considered a close associate of Hindu-nationalist Prime Minister Narendra Modi, a fellow native of Gujarat state.

Opposition parties and other critics say their relationship helped Adani to unfairly win business and avoid proper oversight.