The Financial Supervisory Agency and the Kinki Regional Finance Bureau will question senior officials of Nichiei, the leading nonbank lender of commercial loans, later this week in connection with allegations that the firm has excessively harsh loan-recollection methods, sources said Monday.

Authorities are currently working toward having Nichiei founder and president Kazuo Matsuda appear for voluntary questioning, they added.

Nichiei is the top firm in the area of "shoko loans," which are mainly extended to small and medium-size firms.

FSA officials said that the matter of managerial responsibility, at least, needed to be addressed regarding the case in which a former Nichiei employee was arrested last week on suspicion of threatening a customer to sell his organs to repay loans.

Sources close to the case said the upcoming questioning would probably focus on whether the firm as a whole was involved in using threats and extortion-like methods to have its loans repaid.

Meanwhile, in a related development, in-house manuals on loan collection reportedly used by Nichiei employees were not found during last week's raids of the firm's offices, it was learned Monday.

The missing manuals have led investigators to believe that executives at Nichiei chose to remove them to keep the details of their loan repayment activities hidden, sources close to the case said.

In addition, 25-year-old Eisuke Arai, the arrested former employee, was found to have been initially introduced by Nichiei officials to the customer's lawyer as "an employee of an affiliate and not a Nichiei staffer."

Investigators said they believe this was an attempt to avoid a raid on Nichei by keeping authorities from quickly confirming the identity of the alleged extortionist, and were continuing to question officials close to the case for further information.