PARIS - FIFA announced it has opened an investigation into president Sepp Blatter on Friday as the corruption scandal gripping world soccer took another extraordinary twist.

Soccer's governing body said Blatter would appear before FIFA's ethics committee on Sunday after claims he knew about alleged cash payments at the center of a corruption probe targeting his election rival Mohamed Bin Hammam.

Bin Hammam had demanded the corruption investigation be widened to include Blatter on Thursday as the two men prepare to contest a June 1 election for control of world soccer.