Prosecutors searched the office of Saitama Gov. Yoshihiko Tsuchiya on Friday in connection with his daughter's arrest the previous day over unreported political donations.

Investigators from the Tokyo District Public Prosecutor's Office are trying to determine whether the governor had known about the 113 million yen in unreported donations to his fundraising group, prosecution sources said.

They suspect Tsuchiya may have been informed of the matter by his daughter, Momoko Ichikawa, 53, and may have approved keeping the money off the books, the sources said.