Indian multi-billionaire Gautam Adani's embattled business empire says it has secured $1.87bn (£1.6bn) of investment from a US-based asset management firm.

Florida-headquartered GQG Partners has bought shares in four of the group's companies, Adani told investors.

It marks the first major investment made public by the firm since it was accused of engaging in stock market manipulation and financial fraud by short-seller Hindenburg Research.

Adani Group has denied the allegations.

Adani Group's seven stock market-listed companies had an estimated $135bn wiped off their value since Hindenburg Research's report was published on 24 January.

The GQG investment will be split across four Adani companies, including flagship firm Adani Enterprises.

“This transaction marks the continued confidence of global investors in the governance, management practices and the growth of Adani portfolio of companies,” said Adani Group's chief financial officer Jugeshinder Singh.

“We value GQG's role as a strategic investor in our infrastructure and utility portfolio of sustainable energy, logistics and energy transition,” Mr. Singh added.

Rajiv Jain, chairman and chief investment officer at GQG, said he believed the “long-term growth prospects for these companies are substantial”.

He added that Mr. Adani was “widely regarded as among the best entrepreneurs of his generation.”

In a separate regulatory filing, Adani Enterprises denied media reports that the conglomerate had secured $3bn in credit from a sovereign wealth fund.

“We would like to clarify that the said news item appears to be a market rumour and hence it would be inappropriate on our part to comment on it,” the firm said.

Earlier on Thursday, India's Supreme Court said it had appointed an independent panel to investigate US short-seller Hindenburg Research's allegations against Adani Group firms.

The firm alleged that Adani companies had engaged in decades of “brazen” stock manipulation and accounting fraud.

It also claimed the companies had “substantial debt” which put the entire group on a “precarious financial footing”.

Short-selling is betting that the value of an asset will fall.

dani Group has denied the allegations, calling them an “attack on India”. It had previously said that the Hindenburg report was intended to enable the US-based short seller to book gains, without citing evidence.

Mr. Adani's group has seven publicly-traded companies which operate across a wide range of sectors, including commodities trading, airports, utilities, ports and renewable energy. (BBC)