The largest faction of the ruling Liberal Democratic Party, which is at the center of a slush fund scandal, had once decided to abolish the practice of giving kickbacks to its members after they sold fundraising party tickets, informed sources said on Sunday.

The decision was made by senior officials of the faction, Seiwa Seisaku Kenkyukai, formerly headed by the late Prime Minister Shinzo Abe, ahead of a fundraising party in 2022. But the decision was later withdrawn and kickbacks were given as before, the sources said.

Investigators from the Tokyo Public Prosecutor's Office have questioned former Chief Cabinet Secretary Hirokazu Matsuno, former LDP parliamentary affairs chief Tsuyoshi Takagi and Hiroshige Seko, former LDP secretary-general in the House of Councilors. All are senior members of the faction, and the questioning was done on a voluntary basis, people familiar with the matter said on Monday.