Fifa has launched an investigation into bribery allegations involving four officials, including vice-president Jack Warner and presidential candidate Mohamed bin Hammam. The allegations were made by executive committee member Chuck Blazer. Blazer claims Fifa's code of ethics was violated at a meeting apparently organised by Bin Hammam and Warner. The other two officials are Debbie Minguell and Jason Sylvester from the Caribbean Football Union. The meeting, on 10 and 11 May, was in relation to the Fifa presidential election which takes place on 1 June. Bin Hammam, the president of the Asian Football Confederation, is running against current president Sepp Blatter to be the new head of football's world governing body. The four officials have been called to a hearing of Fifa's ethics committe in Zurich on 29 May. Fifa has announced that Claudio Sulser, the head of the ethics committee, will not take charge of the hearing as he shares Swiss nationality with Bin Hammam's presidential rival Blatter. The committee's deputy chairman Petrus Damaseb of Namibia will instead chair proceedings. The 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."