Police on Thursday arrested six people, including the suspected leader of a major loan-sharking ring, for allegedly laundering profits overseas.

Among them was 54-year-old Susumu Kajiyama, the so-called King of Loan-sharking, who was served with his fourth arrest warrant.

Kajiyama is the former leader of Goryo-kai, a group of gangsters affiliated with Yamaguchi-gumi, Japan’s largest organized crime syndicate.

Police have also obtained an arrest warrant for Atsushi Doden, a 41-year-old employee of the Hong Kong branch of Credit Suisse, on suspicion of involvement in the money laundering operation.

Japanese police have already contacted Doden, who lives in Hong Kong, with the help of the Foreign Ministry and had him hand over his passport. Officials are urging him to return voluntarily to Japan.

According to investigations, Kajiyama and the others conspired to hide the income from some 4.635 billion yen in discount bank debentures bought with loan-sharking profits.

They opened an account in Kajiyama’s name at Credit Suisse’s Hong Kong branch and placed the redemption of the debentures in trust there.

In February 2003, they delivered discount bank debentures to Japan Securities Agents, Ltd., based in Tokyo’s Chuo Ward, on three different occasions via the Tokyo office of Standard Chartered Bank, police said.

The following month, the suspects had Japan Securities Agents serve as the go-between for redemption of debentures involving three other banks and had the money from the transactions deposited in Kajiyama’s bank account in Hong Kong.