An American businessman who tried to improve the way debts are collected in Japan from the oft yakuza-linked intimidation route was arrested last week amid growing pressure by lawyer groups to crack down on unauthorized parties encroaching on their turf.

Steven Gan, president of Advance & Associates Co., had long known he was running a legally risky, if not outright illicit, business. But when he set up his debt-collection firm in 1992, he did so with the conviction that he was helping to change widespread public perceptions of debt collection as a dirty, scary and dangerous affair.

The U.S.-certified public accountant, who was collecting outstanding debts on behalf of more than 600 firms, was arrested Nov. 4 by the Tokyo District Prosecutor's Office. He allegedly collected a combined 15.7 million yen in debts owed to credit card and transport companies without being a licensed lawyer or firm known as a "servicer," for four years up through April.