"If evidence exists that Qatar and Russia received the (World Cup) awards only thanks to bribes, then the awards could be annulled," head of FIFA's auditing and compliance committee Domenico Scala told the 'Sonntagszeitung' weekly.
He stressed though that "this evidence has not been provided" so far.
His comments are the first by a senior FIFA official to even open up the possibility of either Russia or Qatar not hosting the football showpiece in the wake of the recent scandals that have engulfed football's world governing body.
The scandal, which also involves a Swiss probe into the awarding of the 2018 and 2022 World Cups to Russia and Qatar, has led to the resignation of long serving FIFA president Sepp Blatter last week, just four days after his reelection for a fifth successive term.
On Thursday, Britain said it was ready to step in and hold the 2022 World Cup if it was taken away from Qatar, whose hosting has consistently been dogged by controversy.