Ryozo Kato stepped down on Friday from his post as commissioner of Nippon Professional Baseball and hit out at the report of a third-party investigation into a scandal over changes made to the ball for this season.

In a statement released to the media, Kato, who has denied he had any knowledge of changes made to the ball or participated in a cover-up, said, "The (investigators') conclusion was reached before the investigation was done. All I can say is that it is hard to accept."

The 81-page report of the investigation is now available to the public on NPB's official web site.

The report includes comments on various meetings last year within NPB, in which officials of some teams expressed the opinion that the less-lively ball introduced in 2011 was bad for business.

At a meeting of the representatives of the 12 teams last October, some clubs expressed the opinion that, "the best course of action would be to change the ball and keep quiet about it." Officials of other clubs, however, pointed out that even if only the people in that room knew, it would be impossible to keep the change a secret.

Kunio Shimoda, NPB secretary general who implemented the changes to make the ball livelier and who has been suspended for three months and demoted for his actions, responded by saying, "We can't have that. Nobody can say anything."