The president of Chad became enraged four years ago after a Chinese oil and gas company tried to bribe him with $2 million cash secreted in gift boxes, a Senegalese diplomat told a federal jury on Wednesday.President Idriss Deby demanded an explanation from CEFC China Energy after meeting with the conglomerate to discuss oil rights in the African nation, said Cheikh Gadio, a key government witness. Deby, he said, rejected the bribe and asked him why "people believe that all African leaders are corrupt.""I had never seen him in that state," Gadio, a former foreign minister of Senegal, said of the Chadian president. "He was really, really angry — even furious."Gadio brokered business meetings between Deby and Dr. Chi Ping Patrick Ho, a prominent Hong Kong businessman on trial on bribery and money laundering charges. Ho also is accused of lining the pockets of the Ugandan foreign minister and violating the Foreign Corrupt Practices Act.Ho's defense attorneys have argued the cash was a charitable donation that was documented. They say Gadio's testimony should not be trusted and contradicts a paper trail of records.* Sign up to News24's top Africa news in your inbox: SUBSCRIBE TO THE HELLO AFRICA NEWSLETTERFOLLOW News24 Africa on Twitter and Facebook. Gadio was indicted in the case, but federal prosecutors dismissed the charges in exchange for his testimony, the most anticipated of the trial. Prosecutors originally accused him of playing "an instrumental role" in the bribery scheme, connecting Ho to high-ranking African officials and receiving $400 000 for his efforts.Prosecutors say that money, wired to Gadio's consulting firm, was sent through a bank in Manhattan — one of the case's ties to New York.Gadio told jurors Wednesday that Ho was "impressed" by Deby's refusal to accept the cash. Representatives of CEFC China Energy then claimed the money had been intended all along as a donation to the Chadian government, he said.Deby challenged that characterization, Gadio added, saying "donations are not made this way.""The money is not staying in my compound," Deby told Ho and his colleagues, according to Gadio's testimony. "Take it away."Ho's defence attorneys contend CEFC China Energy received nothing in return for the cash payment.But prosecutors allege the company was offered the oil rights "without international competition," though it ultimately purchased other oil rights in Chad from a Taiwanese company.