Both Gautam Adani and his nephew Sagar Adani, a director at Adani Green Energy Ltd, have been summoned by the US Securities and Exchange Commission (SEC) to respond to the charges within 21 days.

Gautam Adani, the billionaire chair of Indian conglomerate Adani Group and one of the world's richest people, could face a long road to trial in the U.S. on criminal charges over his alleged role in a multi-billion-dollar fraud and bribery scheme.