The Qatari on Thursday defiantly refused to withdraw from next week's presidential vote and pressed on with his campaign despite being summoned to answer allegations at a hearing of the world body's ethics committee in Zurich Sunday.
"He's not withdrawing his candidature, despite any rumours and speculation," a spokesperson told AFP, adding that bin Hammam was "confident" of being cleared by the committee.
"He's going there, he's going to present his case and he's confident he's going to be cleared."
Bin Hammam has said explosive claims he tried to rig next Wednesday's FIFA poll—where he is trying to deny Switzerland's Blatter a fourth term as the most powerful man in football—will "vanish in the wind".
"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," he said in a statement Wednesday.
"I am confident that there is no charge to answer and that I will be free to stand in the FIFA presidential election on June 1 as originally planned."
The Asian Football Confederation (AFC) president was carrying on with his regular engagements and flew from Doha to Zurich Thursday to attend a FIFA finance committee meeting, the spokesperson said.
"Nothing has changed. As far as he's concerned, nothing has changed," the spokesperson said.
Bin Hammam, FIFA vice-president Jack Warner and two Caribbean Football Union officials were summoned to the ethics hearing after Chuck Blazer, head of regional body CONCACAF, reported possible misdeeds at a meeting this month.
British media said bin Hammam and Warner are accused of offering $40,000 cash gifts to national associations at the May 10 and 11 talks in Trinidad in return for their votes in the FIFA poll.
The allegations threaten to upend bin Hammam's campaign—which is founded on an anti-corruption theme—and also further besmirch the image of FIFA, which has been dragged through the mire by repeated graft claims.
FIFA opened a separate inquiry earlier this month after accusations made in the British parliament regarding the bidding process for the 2018 and 2022 World Cups.
Former English Football Association chairman David Triesman told a committee he had witnessed "improper and unethical" behaviour by four FIFA voters—including Warner—while campaigning for England's failed 2018 World Cup bid.
On Monday, Qatar denied claims aired in the committee that it paid large bribes to secure its shock victory in the battle to host the 2022 tournament. Bin Hammam, who was instrumental in the bid, has also rejected the allegations.
And in October, an undercover investigation by Britain's Sunday Times alleged that senior officials had offered to sell their votes in the bidding race for the 2018 World Cup.
Despite FIFA's woes, 13-year leader Blatter looks favourite to stay in power after being endorsed by Europe's UEFA and four African regional federations.
The English Football Association is abstaining, claiming it is "difficult to support either candidate".
Blatter has vowed to quash corruption and match-fixing, and this month FIFA announced $20 million in funding to help international police body Interpol tackle Asian betting syndicates.
On Thursday, South Korean prosecutors said they had arrested two suspected fixers and were investigating two players in a probe into betting fraud, highlighting an illicit trade said to be worth hundreds of millions of dollars.