Photo/Illutration Justice Minister Ryuji Koizumi arrives at the prime minister’s office on Dec. 20. (Takeshi Iwashita)

Justice Minister Ryuji Koizumi split from the Nikai faction in the ruling party on Dec. 20, a day after prosecutors searched the group’s office over suspected unreported funds.

Investigators also searched the office of the Abe faction, and several members of that group, the largest in the Liberal Democratic Party, have resigned from their positions in the Cabinet and the LDP executive lineup.

Koizumi, however, said he would remain at his post to fulfill his duties as a Cabinet minister.

“My duty is to do my job fairly and honestly,” Koizumi said. “So I left the faction to avoid any misunderstanding.”

He also suggested he might rejoin the faction after his term as justice minister is over.

One Nikai faction member welcomed this prospect, saying “He may return if and when he can.”

The Nikai faction, led by former LDP Secretary-General Toshihiro Nikai, is believed to have failed to report as income about 100 million yen ($700,000) from sales of tickets to its fund-raising parties. That money was returned to faction members who sold the tickets.

The faction, however, did report the returned money as expenditures, and those recipient lawmakers listed the amounts as revenues in their fund reports, sources said.

The Abe faction is suspected of accumulating 500 million yen in the same manner and returning the money to its ticket-selling members. But unlike the Nikai faction, the Abe faction and its lawmakers did not list any of that money in their fund reports, according to investigative sources.

Although Koizumi indicated that he was leaving the Nikai faction to avoid a possible conflict of interest, opposition lawmakers said he was just trying to deflect criticism, and called on him to resign as justice minister.

They also said Prime Minister Fumio Kishida has bungled the response to the crisis facing the LDP.

Kishida decided on Dec. 20 to appoint former education minister Kisaburo Tokai, an LDP lawmaker unaffiliated with any faction, as chairman of the party’s Policy Research Council, according to senior party members.

Tokai, a Lower House member representing Hyogo Prefecture’s 10th district, will replace Abe faction member Koichi Hagiuda, who has handed in his resignation to Kishida.

Tokai’s appointment will be official as early as Dec. 22, the LDP members said.

Kishida also decided to appoint former Defense Minister Yasukazu Hamada as chairman of the LDP’s Diet Affairs Committee, sources said.

Hamada, another unaffiliated LDP lawmaker, will replace Abe faction member Tsuyoshi Takagi.

Tokai is currently in his 10th term as a Diet member. He previously served as acting chairman of the party’s Policy Research Council.

In the 2020 LDP leadership election, Tokai supported former party Secretary-General Shigeru Ishiba, who lost to Yoshihide Suga in the race.

After Suga resigned as prime minister, Tokai backed former internal affairs minister Seiko Noda, a lawmaker unaffiliated with any faction, in the 2021 LDP leadership race.

Kishida won that election.

(Keishi Nishimura and Yuta Ogi also contributed to this article.)