The panel of five judges on Hong Kong's Court of Final Appeal found Thomas Kwok, the former co-chairman of Hong Kong's largest real estate company Sun Hung Kai Properties Ltd, the city's former number two official Rafael Hui and two others, guilty of the charge of "conspiracy to commit misconduct in public office".
Chief Justice Geoffrey Ma said of Kwok, 65, who had been released on bail during the appeal: "It will now be necessary for him to return to prison".
Kwok looked calm but disappointed and lowered his head when he heard the verdict, according to local media.
He was sentenced to five years in jail and fined HK$500,000 ($64,440) in 2014. He had already served part of that sentence before the appeal.
No more appeals could be made on the case.
The landmark trial tarnished Hong Kong's reputation for clean and efficient governance, with Sun Hung Kai Properties paying Hui millions of Hong Kong dollars in bribes, indirectly through two others, to gain government favor.
In a written summary of the judgment, the court wrote that once Hui had accepted a HK$8.5 million payment, "his independence when he assumed office would be hopelessly compromised and he could not properly discharge his duties nor be trusted to do so".
"The abuse of public trust contemplated by the conspirators was clear", the statement added.
During that period he was involved in important policy matters concerning two large property developments in which SHKP had "substantial interests," the summary noted.
The defendants' lawyers had asserted that Hui did not perform any specific act during his tenure to favour SHKP, and the payment was made shortly before his term started.
But the court dismissed the arguments and said "those who were paying Rafael Hui that sum were not 'running a charity'".
Thomas Kwok's brother and SHKP chairman Raymond Kwok, who was cleared of his charges in relation to the case in 2014, said he felt sad and disappointed at the outcome.
Thomas Kwok's son and executive director of SHKP, Adam Kwok, told reporters after the verdict he felt helpless but accepted the judgment.
"You can say he's careless ... you can say he's overly generous, but I know in his heart he does not have any intention to bribe. He really is an upright person," he said.
The two other defendants in the case are former SHKP executive director Thomas Chan and former Hong Kong Stock Exchange official Francis Kwan. They are now serving a six year and five year prison sentence respectively.
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