UEFA president Michel Platini has vowed to block any attempt to stop the investigation being carried out into the bidding for the 2018 and 2022 World Cups by FIFA's ethics chief.
Michael Garcia, head of the investigatory chamber of FIFA's ethics committee, is currently carrying out his work and Platini says the US attorney must be allowed to continue.
Several FIFA executive committee members were understood to be unhappy at being interviewed by Garcia last week with little advance warning.
Some questioned whether Garcia should remain in the role among suggestions there may be a conflict of interest, given that the USA lost out to Qatar in the 2022 vote.
The decision to award Russia the 2018 tournament is also under scrutiny, with FIFA having admitted it was a mistake to hold the votes for the two bids at the same time in December 2010, leaving Platini determined Garcia be left to complete his investigation.
"I would condemn any possible attempt derail the investigation and I want the process to continue to the very end," said the Frenchman.
Other leading officials at FIFA have also spoken out to defend Garcia's work, including Britain's FIFA vice-president Jim Boyce.
The Northern Irishman, who was not in the position in 2010, confirmed the matter was not raised in last week's executive committee.
"If this had been proposed at the ExCo meeting, or I thought for one moment Garcia would be removed in any fashion from carrying out his full investigation, I and others would be aghast and would have had to consider our positions because things at FIFA have been improving greatly," he said.
Garcia is also investigating reports of payments being made between disgraced former FIFA members Mohamed Bin Hammam of Qatar and Trinidad's Jack Warner in 2011.
Bin Hammam was standing against Sepp Blatter for the FIFA presidency but withdrew from the running after being caught up in a corruption scandal.