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

Opposition politicians from Indian states named in the U.S. indictment of billionaire Gautam Adani denied any wrongdoing on Friday, after Prime Minister Narendra Modi's party said they had to answer for contracts signed while they were in power.

India’s benchmark equity gauge posted its biggest gain since early June, boosted by lenders and market heavyweight Reliance Industries.