Shares of Adani Group firms fell more than 10% in Thursday morning trade, with the group losing around $30bn in market capitalisation. Adani Green Energy, which is the firm at the centre of the allegations, also said it wouldn’t proceed with a $600m bond offering.

The conglomerate has been operating under a cloud in the US since 2023, when a high-profile company published a report accusing it of fraud. The claims, which Mr Adani denied, prompted a major market sell-off.

Reports of this bribery probe have been circling for months. Prosecutors said the US started investigating the company in 2022, and found the inquiry obstructed.

They allege that executives raised $3bn in loans and bonds, including from US firms, on the backs of false and misleading statements related to the firm’s anti-bribery practices and policies, as well as reports of the bribery probe.

“As alleged, the defendants orchestrated an elaborate scheme to bribe Indian government officials to secure contracts worth billions of dollars and… lied about the bribery scheme as they sought to raise capital from U.S. and international investors,” US Attorney Breon Peace said in a statement announcing the charges.

“My office is committed to rooting out corruption in the international marketplace and protecting investors from those who seek to enrich themselves at the expense of the integrity of our financial markets,” he added.

On several occasions Mr Adani met personally with government officials to advance the bribery scheme, officials said.

Michael Kugelman, director of the South Asia Institute at the Wilson Center, called the charges a “body blow” to the tycoon.

“For the last nearly two years, Mr Adani has been trying to rehabilitate his image, and [trying] to show that those earlier fraud allegations levelled by the Hindenburg group were not true, and his company and his businesses had actually been doing quite well,” he told the BBC’s Business Today programme.

But it might be harder for the billionaire, he said, to “shake off” the allegations made by the US Department of Justice.

Mr Adani is a close ally of Indian Prime Minister Narendra Modi. He has long faced claims from opposition politicians alleging that he has benefited from his political ties, which he denies.

The US Attorney positions in the US are appointed by the president. The filing comes just weeks after Donald Trump won election to the White House, pledging to overhaul the US Justice Department.

Last week on social media, Mr Adani congratulated Trump on his election win and pledged to invest $10bn in the US.