Photo/Illutration Kentaro Sonoura, a Lower House member of the ruling Liberal Democratic Party, after giving a news conference Nov. 30 to address allegations of underreporting political funds (Hiroyuki Yamamoto)

A ruling Liberal Democratic Party lawmaker embroiled in a growing money-in-politics scandal finally appears ready to admit allegations he conspired with an aide to underreport his political fund reports to the tune of 40 million yen ($294,000) in violation of the law, sources said.

Tokyo prosecutors are weighing whether to file a summary indictment against Kentaro Sonoura, a member of the Lower House serving his fifth term representing a constituency in Chiba Prefecture, as well as his tax-funded aide, according to the sources.

Sonoura, 50, would face a fine of up to 1 million yen if he is convicted under summary indictment, a simplified proceeding where the accused does not face a formal court trial unless the court decides otherwise.

In such an eventuality, he would also lose his seat as a Diet member and be barred from running in elections for five years, in principle.

Sonoura has been at the center of allegations he violated the Political Fund Control Law by underreporting revenue from fund-raising parties given by a political fund-management organization he represents, while the aide was in charge of accounting.

The aide has maintained during interviews with the Tokyo District Public Prosecutors Office that he notified Sonoura in advance that certain sums of money from fund-raising parties would not be included in the political fund reports, according to the sources.

The aide provided emails, memos and audio tapes to back up his account.

During interviews with investigators on Dec. 13 and 14, Sonoura admitted that his aide informed him beforehand that smaller sums than those raised would be entered in the reports, the sources said.

But he denied giving instructions to falsify the reports.

The sources said Sonoura later told people close to him he would accept whatever prosecutors decide if they determine that he conspired with his aide to underreport his finances.

The fund-management organization and its affiliated political group together underreported a combined 40 million yen. The reports also did not list a host of payments amounting to a sizable sum of money made by them.

Provisions of the Political Fund Control Law place responsibility for properly submitting the annual reports on the individual in charge of accounting, and not the formal head of an organization.

Sonoura, a former newspaper reporter, served as a parliamentary vice minister of the Foreign Ministry and special adviser to the prime minister under the Abe Cabinet.