Fifa has confirmed it is investigating the conduct of four officials following bribery allegations made by executive committee member Chuck Blazer.
Blazer, who is the general secretary of the Concacaf federation, has alleged that violations were committed under the Fifa code of ethics during a meeting organised by Mohamed Bin Hammam and Jack Warner on May 10 and 11 in relation to the upcoming Fifa presidential election, which takes place on June 1.
Bin Hammam is the president of the Asian Football Confederation and is running against Sepp Blatter to be the new president of the sport's world governing body, while Warner is a Fifa vice-president.
A Fifa statement read: "On May 24, 2011, Fifa executive committee member and Concacaf general secretary Chuck Blazer reported to Fifa secretary general Jerome Valcke possible violations of the Fifa code of Ethics allegedly committed by officials.
"In particular, the report referred to a special meeting of the Caribbean Football Union (CFU), apparently organised jointly by Fifa vice-president Jack A. Warner and Fifa executive committee member Mohamed Bin Hammam, which took place on May 10 and 11 2011. This meeting was linked to the upcoming Fifa presidential election.
"In view of the facts alleged in this report, which include bribery allegations, Fifa secretary general Jerome Valcke, in compliance with art. 16 of the Fifa code of ethics, yesterday requested the Fifa ethics committee to open ethics proceedings."
Bin Hammam and Warner, along with CFU officials Debbie Minguell and Jason Sylvester, have been invited to be in position by Friday to attend a hearing in Zurich on Sunday (May 29).
The chairman of the ethics committee, Claudio Sulser, will not oversee the proceedings because he shares Swiss nationality with Bin Hammam's presidential rival Blatter, and this could be construed as a conflict of interests.
The meeting will instead be chaired by the committee's deputy chairman Petrus Damaseb of Namibia.
Swiss MP Roland Buchel told Sky Sports News' chief news reporter Bryan Swanson: "I am not surprised that there's a new case of (alleged) corruption but the investigation comes as a surprise to me.
"It could even be an advantage to Mr Blatter if there are allegations, and maybe no proof, against some people he doesn't like too much.
"They know what happened internally and they have to really clean up their act.
"They know, by the end of the year, there will be a report by the Swiss government and it will become much tougher for Fifa and other international sports federations in Switzerland."
When asked if it was right Fifa was investigating itself, Buchel replied: "No it's not. I think there needs to be an independent investigation."