Under-fire Indian tycoon Gautam Adani's empire has lost more than US$100 billion in value over the past week as shares in several firms plunged again on Thursday, a day after the group cancelled a multi-billion-US-dollar public offering.

The billionaire's sprawling conglomerate has been thrown into turmoil following explosive allegations of accounting fraud on January 24 by US short-seller Hindenburg Research.

Flagship firm Adani Enterprises dived 14 percent – having lost almost 30 percent Wednesday – and has now halved in value since the start of the year.

Other listed companies of Adani's business empire were subject to trading halts after falling as much as 10 percent at the open in Mumbai.

Among them is Adani Total Gas – in which French oil major TotalEnergies holds 37.4 percent – which has now lost 52 percent since January 1.

The latest selling pressure came after Adani late on Wednesday cancelled a US$2.5 billion stock sale that was meant to help reduce debt levels – which have long been a concern – and restore confidence by broadening its shareholder base.

But the issue failed to attract "mom and dad" retail investors and only sold out thanks to large institutional buyers, fellow Indian tycoons and US$400 million from the United Arab Emirates' IHC.

The Adani Enterprises board said in a statement that going ahead with the issue "would not be morally correct" and that it would refund all payments.

Adani himself insisted in a video statement that the "fundamentals of our company are very strong, our balance sheet is healthy and assets robust".

"Once the market stabilises, we will review our capital market strategy," he said, stressing that its record on paying back debt was "impeccable".

Adani, a 60-year-old publicity-shy school dropout, has seen his operations expand at breakneck speed, with shares in Adani Enterprises soaring more than 1,000 percent over the past five years.

Until last week, he was the world's third-richest man, behind Twitter and Tesla owner Elon Musk and France's Bernard Arnault and family.

According to Hindenburg Research, Adani has artificially boosted the share prices of its units by funnelling money into the stocks through offshore tax havens.

Adani said it was the victim of a "maliciously mischievous" reputational attack and issued a 413-page statement on Sunday that it said showed Hindenburg's claims were "nothing but a lie". (AFP)