A former Hong Kong government official pleaded not guilty in New York on Monday to federal charges that he tried to bribe Chad’s president and Uganda’s foreign minister in exchange for oil rights for a Chinese energy company.

The former official, Chi Ping Patrick Ho, and a former foreign minister of Senegal, Cheikh Gadio, were arrested in November and charged with money laundering and violations of the Foreign Corrupt Practices Act.

Trained as an eye surgeon in the United States, Mr. Ho, 68, served as Hong Kong’s home affairs secretary from 2002 to 2007. After leaving office, he became the secretary general of the China Energy Fund Committee, a Hong Kong research organization that gets financing from CEFC China Energy Company, a major energy conglomerate that is based in Shanghai and has ties to the Chinese Communist Party.

According to United States prosecutors, Mr. Ho took part in two bribery schemes. One involved a $2 million bribe offered to President Idriss Déby of Chad “in exchange for securing business advantages” for the conglomerate in its effort to obtain oil rights in the country without facing international competition. Mr. Gadio was the conduit for the offer, and was compensated by Mr. Ho with $400,000 wired through New York, the prosecutors said.