ZURICH -- With FIFA's presidential election just a week away, football's governing body said Wednesday it is investigating challenger Mohamed bin Hammam for bribery in his campaign to unseat Sepp Blatter.
FIFA summoned Asian Football Confederation leader bin Hammam and FIFA vice president Jack Warner to an ethics hearing on Sunday to face allegations of corruption during the Qatari official's campaign visit to Trinidad two weeks ago.
The allegations -- leveled by Warner's longtime ally Chuck Blazer of the United States -- could well wreck bin Hammam's already fading hopes of defeating Blatter in the June 1 vote by FIFA's 208 national members.Bin Hammam faces being provisionally suspended from all football duties by the FIFA ethics committee.
He denied wrongdoing and suggested, on "a difficult and painful day for me," that the accusations were instigated by Blatter's camp.
"This move is little more than a tactic being used by those who have no confidence in their own ability to emerge successfully from the FIFA presidential election," bin Hammam wrote in a statement published on his official website.
Warner also rejected the allegations, and said he was "unaware of the particulars" of FIFA's investigation. The veteran FIFA official also questioned why the case was made public now.
"It is interesting to note the timing of these allegations and the hearing scheduled days before the FIFA presidential elections," Warner said in a statement.
Blazer's report, which FIFA said "include bribery allegations," prompted secretary general Jerome Valcke to ask the governing body's ethics committee to investigate.
Blazer, the highest-ranked American in world football, told The Associated Press he did not want to comment further ahead of Sunday's hearing, involving his long-standing FIFA executive committee colleagues.
"We filed a comprehensive file covering what we believe to be various types of violations," Blazer said.
The ethics panel can provisionally suspend officials under suspicion while it gathers evidence for a full hearing. It took this path when investigating two of bin Hammam's FIFA executive committee colleagues prior to the 2018 and 2022 World Cup votes last December.
Bin Hammam, under the terms of a provisional ban, could effectively be barred as an election candidate.
"I am confident that there is no charge to answer and that I will be free to stand ... as originally planned," bin Hammam wrote. "If there is even the slightest justice in the world, these allegations will vanish in the wind."
FIFA said the allegations related to bin Hammam's meeting with 25 Caribbean football leaders on May 10-11 in Warner's native Trinidad to lobby for support.
"This meeting was linked to the upcoming FIFA presidential election," FIFA said.
Blatter's campaign adviser, Brian Alexander, said the FIFA president would not comment on the case.
Bin Hammam helped organize the hastily arranged meeting after he was unable to attend the annual congress of the Confederation of North, Central America and Caribbean Association Football (CONCACAF) one week earlier in Miami.
The Qatari official was denied a visa to enter the U.S., despite traveling on a diplomatic passport. His campaign's administrative oversight left Blatter a clear run to lobby for votes in Miami.
Warner has long been a key powerbroker in FIFA politics and his backing was seen as vital to bin Hammam's hopes. Blatter has been endorsed by confederation leaders in Africa, Europe, Oceania and South America.
Warner's 35-member confederation has not yet officially backed either candidate.
One Caribbean official who attended the meeting in Trinidad told the AP that bin Hammam only gave a power point presentation and had dinner with delegates.
"I was actually surprised to hear some of the things I'm hearing in the press and seeing," said David Hinds, the general secretary of the Barbados Football Association. "It was just a presentation. A presentation that he did in one of the ballrooms. And that was it. We had dinner that evening and he flew out and then we went home."
Bin Hammam and Warner are both scheduled to be in Zurich on Thursday for a meeting of FIFA's finance committee, though Warner is not expected to travel to Zurich. FIFA's executive committee chaired by Blatter next meets on Monday.
They face lengthy suspensions from all football duties if bribery allegations are proven. Both were re-elected unopposed this year to lead their continental bodies for four more years.
Two other Caribbean Football Union officials, Debbie Minguell and Jason Sylvester, are also being investigated by FIFA.
The four people under suspicion have been invited to "take a position" by Friday and report to the ethics panel on Sunday, FIFA said.
Corruption in FIFA has been a prominent campaign theme after a series of financial and vote-buying scandals severely damaged its reputation during Blatter's 13-year presidency.
Bin Hammam appeared to have been damaged by association with corruption more than Blatter during their two months of electioneering.
Bin Hammam was a key player in Qatar's successful bid to host the 2022 World Cup. Qatar was accused in a British Parliamentary hearing of paying $1.5 million bribes to two African FIFA executive committee members, Issa Hayatou and Jacques Anouma. They deny the claims.
On Wednesday, a whistleblower from the Qatar bid had been scheduled to submit evidence to Valcke and FIFA legal director Marco Villiger in Zurich.
However, FIFA said the whistleblower "decided not to attend the meeting" based on legal advice.
FIFA said Warner and bin Hammam will face an ethics panel chaired by Namibian judge Petrus Damaseb.
Ethics committee chairman Claudio Sulser stepped aside to avoid a conflict of interest because he shares Swiss nationality with Blatter.
As FIFA's top administrator, Valcke must decide whether to refer Qatar's bid to the ethics panel.
Last week, Blatter did not encourage or rule out the possibility of reopening the 2022 vote if corruption is proved. The other 2022 bids came from the U.S., Australia, Japan and South Korea.
Qatar defeated the U.S. 14-8 in the final round of voting by FIFA's executive committee. Two members, Amos Adamu and Reynald Temarii, were suspended two weeks before the vote following an ethics probe. Adamu got a three-year ban for seeking bribes and has appealed to the Court of Arbitration for Sport.
Blazer was openly critical of Qatar's plans in public, and within FIFA's executive committee which he joined in 1996.
Calls to his mobile telephone were not answered on Wednesday.
Bin Hammam also has sat at FIFA's high table for 15 years, while Warner was elected to his seat in 1983.
Warner, along with three more FIFA executive colleagues, was accused of unethical behavior in the British hearing this month.
The former head of England's failed 2018 World Cup bid, David Triesman, alleged the 68-year-old Trinidad government minister asked for money to build an education center and buy 2010 World Cup broadcast rights for Haiti.
Warner denied the allegation. He was censured by FIFA in 2006 after his family was found to have profited from selling overpriced World Cup ticket packages to Trinidad fans for that year's World Cup in Germany.
AP National Writer Nancy Armour in Chicago contributed to this report.