FIFA has summoned senior Nigerian and Oceanian officials Amos Adamu and Reynald Temarii to a committee meeting on Wednesday which is investigating allegations of votes being sold in World Cup bidding.
"I can confirm that Temari and Adamu have been summoned to appear before a meeting of the ethics committee tomorrow," a spokeswoman for world football's governing body told AFP on Tuesday.
A British newspaper reported on Sunday that Adamu and Temarii, who are members of FIFA's executive committee, had offered to sell their votes in the bidding race for the 2018 World Cup to undercover journalists posing as lobbyists.
The ethics committee is in charge of an investigation launched by Zurich-based FIFA this week following the report.
FIFA said in a statement on Monday that it had "opened proceedings against two members of the FIFA Executive Committee to ascertain whether they have violated the FIFA Code of Ethics," and will consider "provisional measures" if necessary.
Football's governing body also revealed that the ethics committee would investigate any agreements between member associations, warning that they could be a clear violation of the bidding rules for the World Cup.
The governing body did not specify which countries would be under scrutiny.
England, Russia, and joint bids by Spain-Portugal and Netherlands-Belgium are in the running to host the 2018 World Cup. For 2022, the contenders are Qatar, Australia, the United States, Japan and South Korea.
Last Friday, US Soccer withdrew its bid to host the 2018 event to focus on 2022, leaving an all European field competing for 2018, while England in turn withdrew from the 2022 race.
FIFA is due to announce on December 2 which countries will host both events.