Sanraizu Fuzu, whose grilled eel products were already under investigation in another incident, now faces further scrutiny from the Agriculture, Forestry and Fisheries Ministry.
Officials are investigating whether the company purchased eels from China and other countries and repackaged them as Japanese products, The Yomiuri Shimbun reported Saturday.
Under suspicion are the approximately 3.3 million eels per year that the company sends to 70 supermarkets and shops in eastern Japan. When government officials visited the Sanraizu Fuzu fish farm, they reportedly found only one of the farm's nine ponds containing eels. The company had no documents showing the purchase of food for the eels
A Sanraizu Fuzu factory worker confirmed suspicions to The Yomiuri Shimbun.
"It's very rare to see live eels at the factory. We unwrap grilled eel packages, place the product on a different tray and wrap them again," the worker said.
Another employee claimed to have seen boxes marked "Product of China" at the Sanraizu Fuzu facility.