The challenger's campaign said Monday it was approached by an individual who offered details on Blatter's finances and claimed to be able to help deliver dozens of votes in the head-to-head contest for the FIFA presidency. It did not identify the individual.
It said it rejected the offer and informed police authorities, but did not disclose which country's law enforcement was contacted.
However, the Jordanian prince — a FIFA vice-president — did not notify football's governing body of the attempt to corrupt the election or that Blatter's purported private information was apparently being touted.
"The FIFA administration has not been informed of any such matter," FIFA said in a statement to The Associated Press. "However, the body to deal with such cases is the investigatory chamber of the independent ethics committee."
Asked why the ethics body was not informed, the prince's campaign team told the AP that it "did not want to do anything that could jeopardize the police investigation."
"Our goal was not to create a campaign issue, but to properly react to an approach made to us that appeared to involve criminal activity," the prince's team said.
On Friday, Blatter, who has been FIFA president since 1998, will face the first contested vote for the job since 2002. Prince Ali, whose brother is Jordan's King Abdullah, is the only challenger after former Portugal great Luis Figo and Dutch football federation president Michael van Praag withdrew their candidacies last week.
Information about the alleged offer to help oust Blatter was released in a statement from Quest, a corporate intelligence firm run by former London police commissioner John Stevens. Quest said it has been working for the prince's campaign in order to guard "against any threats to the integrity of the election process ... or campaign dirty tricks."
"In April, Prince Ali's campaign team was contacted by ... (an) individual who claimed the ability to deliver 47 votes, in addition to what appeared to be illegally obtained information relating to the financial activities of Mr. Sepp Blatter," Quest said in a statement authenticated by the campaign's external communications advisers.
"The campaign referred the matter to Quest, instructed them to reject the offer and to engage with relevant law enforcement agencies. The individual's claims to have obtained information illegally are now under police investigation."
Quest said the potentially illegal offers did not come from people claiming to work for any of FIFA's 209 member associations.
A new FIFA code of conduct was published three years ago in the wake of a bribery scandal that saw Mohamed bin Hammam withdraw from the ballot days before the 2011 FIFA presidential election, which Blatter won unopposed.
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