Prosecutors have questioned the person in charge of accounting for the Liberal Democratic Party's largest faction, led by former Prime Minister Ryutaro Hashimoto, in connection with an undeclared donation the group received in 2001 from a scandal-tainted dentist association, sources said Thursday.

They said prosecutors might establish a criminal case over a possible violation of the Political Funds Control Law. The accountant, who was not identified, is suspected of deliberately concealing 100 million yen that Sadao Usuda, 73, then chairman of the Japan Dental Association, allegedly handed Hashimoto, they said.

Under the law, someone entering a fictitious account in an annual political funds report can face imprisonment of up to five years or a fine of up to 1 million yen.