NHK has learned a lawmaker of the main ruling Liberal Democratic Party has likely received about 50 million yen, or about 350,000 dollars, in kickbacks with regard to selling tickets for fund-raising parties.

The LDP has been under scrutiny as some party factions have been underreporting revenues from political fund-raising parties.

Japan's political funds control law obliges political organizations to record in their funding reports the total revenue from such party tickets.

The LDP's largest faction, the Seiwa policy study group, also known as the Abe faction, is thought to have paid out kickbacks to lawmakers who exceeded their quotas of ticket sales.

The faction, once led by the late Prime Minister Abe Shinzo, is accused of failing to register the extra income and payouts to lawmakers as expenditures in its reports.

The total amount of the kickbacks is estimated to have reached several million dollars during the five-year period through the end of 2022.

Some lawmakers are considered to have received kickbacks of over 68,000 dollars each during the period.

Informed sources told NHK that one of them likely has received about 350,000 dollars during the same period.

The political organizations of these lawmakers who received the kickbacks have allegedly failed to write the payment as income in their political fund reports.

Tokyo prosecutors are reportedly considering questioning the lawmakers on a voluntary basis after the current Diet session closes on Wednesday next week.

They are mobilizing additional prosecutors from across the nation to expand the scope of the investigation to trace the flows of funds and unravel the questionable case.