England, Russia, Spain/Portugal and Holland/Belgium are bidding for the 2018 World Cup while USA, Australia, Qatar, Japan and South Korea are campaigning to host the 2022 tournament.
FIFA's ethics committee will this week start investigations on a Sunday Times expose of two members of FIFA's 24-man executive committee, Amos Adamu from Nigeria and Tahiti's Reynald Temarii, president of the Oceania Football Confederation.
Reporters from the newspaper posed as English-based lobbyists for a consortium of private American companies who wanted to help secure the World Cup for the United States.
At an initial meeting in London, Adamu is said to have told reporters that he wanted $800,000 to build four artificial football pitches in his home country.
Temarii is also alleged to have asked for a payment, in his case to finance a sports academy.