The U.S. Securities and Exchange Commission has summoned Indian billionaire Gautam Adani over U.S. corruption allegations linked to an explosive federal indictment against him, according to a court filing.

The SEC is suing Adani Group chief and his nephew Sagar Adani, alleging they engaged in hundreds of millions of dollars in bribes to help an Adani company while “falsely touting respect by the company’s anti-corruption principles and laws in $750 million deal. bond offering.”

The subpoena requires a response within 21 days, according to the filing Wednesday in federal court for the Eastern District of New York. The SEC’s suit seeks unspecified monetary penalties and restrictions on the Adanis as officers of public companies.

Adani Group representatives did not immediately respond to a Reuters request for comment on Sunday.

The group has denied the criminal accusations, calling them “baseless.” The group’s chief financial officer said the indictment related to an Adani Green Energy contract that represents about 10% of its business and that no other companies in the conglomerate were accused of wrongdoing.

Federal prosecutors issued arrest warrants for Gautam and Sagar Adani, alleging they participated in a $265 million scheme to bribe Indian officials to obtain electricity supply contracts.

Authorities said Adani and seven other defendants, including his nephew Sagar, agreed to bribe Indian government officials to secure contracts expected to bring in $2 billion in profits over 20 years and develop India’s largest power plant project solar from India.

The crisis is the second in two years to hit the ports-to-power conglomerate founded by Adani, 62, one of the world’s richest people. The consequences were immediate, as billions of dollars were wiped from the market value of Adani Group companies and the president of Kenya canceled a massive airport project with the group.