Tokyo prosecutors have reportedly questioned former industry minister Nishimura Yasutoshi on a voluntary basis in connection with a money scandal embroiling factions of the main ruling Liberal Democratic Party.

Sources say Nishimura has now become the last of the six executive members of the largest LDP faction who have been questioned over the suspected off-the-book flow of funds. The faction was formerly led by the late Prime Minister Abe Shinzo.

The sources say the prosecutors also questioned former LDP policy chief and Abe faction member, Shimomura Hakubun, on a voluntary basis.

The Abe faction is said to have paid kickbacks to offices of member lawmakers who sold fundraising party tickets in excess of their quotas.

It is suspected that the faction did not record this revenue from fund-raising events in its political funds reports.

Prosecutors raided the Abe faction office earlier this month on suspicion of violating the political funds control law.

Most of the faction members, including its six top executives, are found to have accepted kickbacks. Those lawmakers' offices are also suspected of not including the money in their political funds reports.

Prosecutors earlier questioned on a voluntary basis the five other leading members of the Abe faction.

They are former Chief Cabinet Secretary Matsuno Hirokazu, former LDP Diet affairs chief Takagi Tsuyoshi, former LDP Upper House secretary-general Seko Hiroshige, former education minister Shionoya Ryu and former LDP policy chief Hagiuda Koichi.

Several of the questioned lawmakers have served as he faction's secretary-general. Shimomura held the position from January 2018 through September 2019. Matsuno succeeded him in the post through October 2021, followed by Nishimura and Takagi.

The prosecutors are believed to have asked them for details about why the faction failed to report part of the revenue from the fund-raising events.