Prosecutors on Thursday appealed a district court ruling that acquitted a Japanese man formerly employed by Credit Suisse in Hong Kong of money-laundering on behalf of a gangster who operated a loan-sharking network for the mob.

The Tokyo District Court acquitted Atsushi Doden, 43, on March 22 of charges of laundering some 9.4 billion yen for a man who operated a loan-shark network affiliated with the Yamaguchi-gumi, Japan's largest underworld syndicate.

The court said in handing down the ruling that there were reasonable grounds for doubting he knew the money entrusted to him was profits from criminal activities.

Prosecutors had demanded three years in prison and a 3 million yen fine, saying Doden had played an indispensable part in the crime of illegal lending.