Japanese prosecutors have questioned former economy minister Yasutoshi Nishimura and former education minister Hakubun Shimomura on a voluntary basis over a political funds scandal involving the ruling Liberal Democratic Party's largest faction, sources close to the matter said Saturday.

The faction, formerly led by slain Prime Minister Shinzo Abe, is alleged to have failed to declare hundreds of millions of yen in revenue from its fundraising parties in political funding reports and creating slush funds to transfer to its members, the sources said.

With the latest move on Nishimura, six senior members of the faction have now been questioned, including former top government spokesman Hirokazu Matsuno and former LDP policy chief Koichi Hagiuda earlier this month.

The prosecutors are considering building a criminal case against the faction's accountant in charge while also looking into the level of involvement of the senior members of the faction over potentially systematic efforts to create a slush fund.

The Political Funds Control Act requires an accountant to submit a report on income and expenditures, and a failure to report can be punishable by imprisonment for up to five years or a fine of up to 1 million yen. Lawmakers could also face criminal charges if suspected of colluding with accountants.

The prosecutors suspect the Abe faction circulated back extra revenues raised by its member lawmakers from selling tickets for the faction's gatherings.

The amount is believed to have totaled around 500 million yen ($3.5 million) over five years through 2022, a period for which the statute of limitations has not expired under the political funds control law, according to the sources.

Nishimura, who was replaced as economy, trade and industry minister earlier this month over the scandal, previously served as the faction's secretary general from October 2021 through August 2022.

Yasutoshi Nishimura attends a press conference at the Economy, Trade and Industry Ministry in Tokyo on Dec. 14, 2023, after submitting his letter of resignation as economy minister amid a political fundraising scandal involving himself and other ruling Liberal Democratic Party lawmakers belonging to the party faction previously led by former Prime Minister Shinzo Abe. (Kyodo) ==Kyodo

Shimomura served as LDP policy chief in the past.

In questioning the senior lawmakers, the prosecutors are focusing on their involvement in an aborted 2022 proposal in the Abe faction to halt the practice of transferring the extra funds to its members. This proposed change did not materialize due to opposition from faction members.

The three others who have been questioned are former LDP Diet affairs chief Tsuyoshi Takagi, who has been in the secretary general post since August 2022, Hiroshige Seko, former secretary general of the party in the House of Councillors, and Ryu Shionoya, who is currently the de facto head of the Abe faction.

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