Patrick Ho flew to New York in fall 2014. His intention, according to the Justice Department, was to bribe African officials on behalf of a private Chinese conglomerate with global ambitions and enormous wealth.

In meetings at the United Nations, Mr. Ho, a former Hong Kong civil servant, laid the groundwork for millions of dollars of payments to the president of Chad and Uganda’s foreign minister in exchange for oil rights in the two countries, federal prosecutors say.

The accusations against Mr. Ho, detailed in a criminal complaint filed in Manhattan, became public this week after officials charged him and Cheikh Gadio, a former Senegalese official who acted as a fixer for Mr. Ho, with international money laundering and violations of the Foreign Corrupt Practices Act. Mr. Gadio was arrested on Friday and Mr. Ho on Saturday, the Justice Department said.

The complaint does not name the Chinese company Mr. Ho represented, but the specifics of the case make clear the company’s identity: CEFC China Energy Company.