“If evidence should emerge that the awards to Qatar and Russia only came about thanks to bought votes, then the awards could be invalidated,” Scala said in an interview published on Sunday. “This evidence has not yet been brought forth.”

Russia and Qatar have previously denied wrongdoing in the conduct of their bids for the 2018 and 2022 tournaments, which were not the subject of charges announced by U.S. prosecutors last week against FIFA officials.

Scala had made similar comments in 2013 but events over the last two weeks, which included a dawn police raid in Zurich and the arrests of several FIFA officials on U.S. charges, have added urgency to his remarks.