With over 2,800 sick from deliberate poisoning with a pesticide at a Japanese frozen food manufacturers, the presidents of the firm did the only honorable thing: fall on their swords.

A 49-year-old contract worker at the plant where frozen food was laced with the agricultural chemical malathion has been arrested by the Gunma prefectural police on suspicion of obstructing business. The suspect worked at the Gunma plant of Aqli Foods Corp., a subsidiary of leading food maker Maruha Nichiro Holdings Inc.

The man is suspected of lacing frozen food produced at the plant with malathion on four occasions in October. About 2,800 people across the country have complained of feeling ill after eating pizza and other frozen food produced at the plant.

The presidents of Maruha Nichiro Holdings and Aqli Foods have announced they will resign at the end of March to take responsibility for the latest incident.

The companies failed to respond promptly, taking 1½ months to launch a self-imposed recall of products after receiving a complaint in November of an odd odor from pizza manufactured at the plant.