Toshiki Abe, 49, is charged with spraying the pesticide malathion on food at the AQLI Foods Corp. plant, a subsidiary of Maruba Nichiro Holdings Inc., the Yomiuri Shimbun reported Saturday.
Some 2,843 people complained of diarrhea, vomiting and other symptoms after eating the food. Maruba Nichiro issued a recall for the products Dec. 29 after announcing the detection of malathion.
Police said Abe's clothes smelled of malathion when he was arrested at the plant, in Gunma Prefecture on the country's main island of Honshu.
Investigators said the pesticide appeared to have been added to the food immediately before it was packaged.
The company said about 86 percent of the food has been recalled.
Investigators said Abe added the malathion four separate times between Oct. 3 and Oct. 7, Kyodo News reported.
The amount of the pesticide applied was determined to be 2.6 million times higher than acceptable levels.
Abe told police he did not remember spraying the malathion.