premise: World football governing body FIFA has suspended a list of international referees submitted by Kenya last month after allegations of graft in their recruitment and ordered immediate investigations.
  In a letter to Kenya Football Federation (KFF), FIFA deputy general secretary Michael Schallhart said the football world governing body had launched immediate probe into the exercise.
  "The FIFA Referees Committee has decided to suspend the lists of nominations submitted by Kenya Football Federation (KFF) until further notice," Schallart said in a letter to KFF.
  An investigation has been started. The graft allegations were revealed last month by Kenya Football Referees Association secretary-general G.M.T. Ottieno, a week after FIFA suspended the east African nation from international competition indefinitely.
   What does the exercise refer to?
hypothesis: allegations of graft in their recruitment