Reports in Spain claim the Spanish Football League (LFP) is examining a Primera Division game between Espanyol and Osasuna that ended 1-1 in Barcelona last May.
Both teams were fighting to defend their top-flight status.
“I deny that there was match-fixing,” Kiko told the Spanish press. “We are all in agreement in the locker room with what the club has already stated.”
While the LFP has not announced an official investigation, each club has declared there was no wrongdoing.
Kiko insists he and his team-mates have nothing to hide.
“No one has ever let me down and I trust all my team-mates, the ones that are here and the ones of previous years,” he said. “I remember that game and there was nothing strange about it.
“All of this makes no sense. We are all calm. I don’t know where this is coming from.”
Espanyol finished 14th in La Liga last season, just three places clear of Osasuna, who were relegated.