Banks that have given loans to Seibu group companies, including group leader Kokudo Corp., have launched probes to investigate the quality of their assets, financial sources said Tuesday.

The investigations follow revelations that Kokudo, an unlisted firm that runs a hotel chain and sports facilities, and some other group companies -- including Seibu Railway Co. -- reported false information about stockholders in their financial statements.

The Seibu group's combined borrowings from banks total 1.3 trillion yen, with Seibu Railway's share amounting to more than 700 billion yen from about 30 lenders as of the end of September, the sources said. The lenders include Mizuho Corporate Bank, Chuo Mitsui Trust and Banking Co., and the governmental Development Bank of Japan, they said.

Group firms have received loans with favorable terms and conditions due to the creditworthiness of former Kokudo chairman and billionaire Yoshiaki Tsutsumi.