Zurich: FIFA's Director of Communications and Public Affairs Walter De Gregorio resigned with immediate effect on Thursday.
The former Swiss journalist joined FIFA in 2011 and will continue to serve the international sports body on a consultancy basis until the end of this year.
He worked on Blatter's campaign team during that year's presidential election. He is believed to be closely tied to outgoing FIFA president Sepp Blatter.
"Walter De Gregorio has decided to relinquish his office with immediate effect as Director of Communications & Public Affairs," a FIFA statement said.
"Mr De Gregorio joined FIFA on 14 September 2011 and will serve FIFA on a consultancy basis until the end of this year," it added.
De Gregorio's deputy Nicolas Maingot would resume the role ad interim, world football's governing body said.
"Walter has worked incredibly hard for the past four years and we are immensely grateful for all he has done. I am glad we will be able to continue to draw on his expertise until the end of the year," Jerome Valcke, FIFA secretary general, said in the statement.
FIFA is currently involved in several corruption investigations with Swiss authorities probing the legality of the bidding process of the 2018 and 2022 World Cups, awarded to Russia and Qatar, respectively.
Both Russia and Qatar have repeatedly denied any wrongdoing.
The United States' Federal Bureau of Investigation (FBI) has already arrested seven top FIFA officials and indicted 14 people for financial misdemeanour.
FIFA president Sepp Blatter resigned days after getting elected for a fifth four-year term but will continue till a successor is chosen by the world football governing body's executive committee.
His successor is likely to be chosen on December 16 at an emergency executive committee meeting.
Blatter is being probed by the FBI for his role in the scandal. Valcke's role too is under the scanner even though he has not been indicted by the US.