Prosecutors on Friday began questioning Masakuni Murakami, a former senior Liberal Democratic Party lawmaker, about money and favors he allegedly received from KSD, a government-authorized industrial mutual aid organization at the center of a widening bribery scandal, prosecution sources said.

The Tokyo District Public Prosecutor's Office quizzed Murakami, 68, ahead of his testimony on Wednesday regarding the KSD scandal as a sworn witness at the House of Councilors Budget Committee, the sources said.

The committee adopted a resolution earlier Friday to summon Murakami, who tendered his resignation to the Upper House on Thursday, for a two-hour questioning session Wednesday, beginning at 1 p.m.