Disgraced former FIFA official Amos Adamu lost his appeal against a three-year ban from football for seeking bribes during bidding for the 2018 and 2022 World Cups.
The Court of Arbitration for Sport upheld a judgment by FIFA's ethics committee to expel Adamu from football until October 2013.
A panel of three arbitrators said the ban "was even relatively mild given the seriousness of the offense."
"The CAS Panel stressed that it was of crucial importance that top football officials should not only be honest, but should evidently and undoubtedly be seen to be honest," the court said.
Sport's highest court also delivered a vindication of British newspaper The Sunday Times, which was roundly criticised by senior FIFA officials as "sensationalist" and "unethical" when its undercover work exposed wrongdoing at the heart of football's world governing body in October 2010.
CAS said its panel was "comfortably satisfied" that the Rupert Murdoch-owned newspaper had accurately shown that Adamu was seeking an illegal kickback.
Adamu was secretly filmed by undercover reporters posing as World Cup bid lobbyists asking them for $800,000 (€600,000) to influence his vote. He said the money would pay for artificial football fields in his native Nigeria.
Adamu told The Associated Press over the phone on Friday that he "had not heard" the verdict and declined to comment.
FIFA said it was "satisfied" by the court's ruling.
"This CAS decision further underlines FIFA's zero tolerance and clear stance against any breach of the FIFA Code of Ethics," football's world governing body said in a statement.
In a hearing held last October, lawyers for Adamu argued that the evidence was inadmissible because it might have been illegally obtained under Swiss law.
The panel, sitting as an international court, dismissed that line of defense as "mere circumstance" and, by the way, "there has been no ordinary judge declaring that the evidence was unlawfully obtained and prohibiting its use."
What's more, the panel "was even not sure that the Sunday Times journalists acted illegally."
"(Adamu) has also claimed a violation of his personality rights," CAS said. "With respect to the behaviour of Dr. Adamu, the CAS panel was comfortably satisfied that he was far from actively and unambiguously refusing the improper offer set forth by the alleged lobbyists."
The court's approval of the newspaper's work contrasted with past criticism by FIFA's ethics chairman Claudio Sulser, who said the original report was "sensationalist" and "twisting the facts" by presenting edited footage of Adamu's demands.
When the story broke, FIFA vice president Mohamed bin Hammam questioned whether the newspaper's tactics were more unethical than his Nigerian colleague. Bin Hammam has since been banned for life in a separate bribery scandal.
The first scandal implicated Adamu and five other senior officials, and plunged FIFA into turmoil weeks before the December 2010 votes.
Adamu was excluded and lost his seat representing Africa on the FIFA executive committee.
Until then, the former Nigerian government adviser was expected to be a strong candidate to succeed Issa Hayatou as president of the 54-nation Confederation of African Football.
Adamu was also ordered to pay FIFA a fine of 10,000 Swiss francs ($11,100; €8,300).
His case was the first time a CAS panel has scrutinized FIFA's code of ethics, which FIFA used to ban bin Hammam last year, after the former presidential candidate was judged to have arranged bribes for voters in the Caribbean.
Bin Hammam will challenge FIFA at CAS on April 18-19 to try to overturn his expulsion.
CAS is preparing verdicts in two more cases of alleged FIFA corruption by former executive committee members.
Amadou Diakite of Mali and Ahongalu Fusimalohi of Tonga both appealed their two-year sanctions based on Sunday Times evidence. They allegedly advised reporters posing as lobbyists how to bribe FIFA officials and to pay $1 million (€750,000).
Diakite was removed from FIFA's referees committee and Fusimalohi lost his job as chief executive of Tonga's football association. Two more former FIFA executive committee members accepted their bans for giving bribes advice and did not appeal to CAS.
Tunisian lawyer Slim Aloulou served a one-year ban and lost his position chairing FIFA's disputes resolution panel. Ismail Bhamjee of Botswana got a four-year ban, four years after he was removed from the executive committee for scalping tickets at the 2006 World Cup in Germany. He was replaced by Adamu as one of Africa's four delegates in FIFA's high command.
The Sunday Times probe also resulted in then FIFA vice president Reynald Temarii of Tahiti serving a one-year ban for breaking confidentiality rules.