GQG Partners , which has a near 20% stake in India's Adani Group, saw its Australia-listed shares plunge 23% on Thursday after Gautam Adani, the conglomerate's chair, was indicted in the U.S. over charges of bribery and fraud.

Adani, an Indian business magnate and one of the richest men in Asia, faces new allegations of fraud to secure solar energy supply contracts.

Indian billionaire Gautam Adani, one of Asia’s richest men, may be facing his biggest challenge yet with an indictment by U.S. prosecutors for alleged fraud and bribery. But it’s unclear just how the case will affect his businesses and own future — as well as the Indian economy and government.