A producer at Nippon Television Network Corp. has bribed TV viewer rating monitors in a bid to manipulate the viewer ratings of his own shows, it was learned Friday.

Nippon Television President Toshio Hagiwara apologized over the scandal in a news conference held at the firm's headquarters in Tokyo, promising an in-house probe into the matter.

"I deeply apologize to the viewers, sponsors and all other people involved in the broadcasting industry," Hagiwara said. "The sin of damaging the fairness of the viewer rating survey is significant. It is a despicable betrayal of (others) who make TV programs and is blasphemy."