Prime Minister Shinzo Abe on Thursday evening apologized over the arrest of a former justice minister he had appointed, saying the action was “regrettable” and that he “feels acutely” his responsibility of having appointed the individual in the first place.

“I apologize to Japanese people from the bottom of my heart,” Abe said at the beginning of his hourlong news conference and bowed his head lightly. “We, the members of the Diet, should take critical public opinion seriously and shape up once again taking (the arrest) as an opportunity.”

Public prosecutors on the same day arrested Katsuyuki Kawai and his lawmaker wife, Anri Kawai, over vote-buying during her successful Upper House election bid last summer. Katsuyuki Kawai previously served as Abe’s adviser and justice minister.