In late November in Jamnagar, India, the scions of two of the most powerful families in the world stood face-to-face. On one side was 30-year-old Anant Ambani, son of one the richest men in Asia. On the other was Donald Trump Jr. For months, the Trump administration had been on the offensive against the sprawling Ambani energy empire, placing it at the center of an escalating tariff campaign against India. But after Trump Jr. touched down, the two men toured the Ambanis’ private zoo, and at night they performed a Gujarati folk dance, grinning as they moved together to the music.

Four months later, an obscure Texas startup called America First Refining announced that it had received a nine-figure investment from the Ambanis’ company. The deal puzzled numerous energy investors familiar with the project, which aims to build the first major new oil refinery in the U.S. in about 50 years. The company is run by a serial entrepreneur with a history of bankruptcy and lawsuits alleging fraud. After more than a decade of failed attempts to raise money, blown deadlines and rebrands, it had been floundering.

America First Refining’s unexpected breakthrough came after it forged a previously unreported relationship with Trump Jr., who secretly acquired a stake in the startup, according to records and seven people familiar with the company. The new details reveal the role the president’s son has played in a theme of Trump’s second term: overseas investors with interests before the administration putting money into the Trump family’s business interests.