Hong Chang Corporation of Santa Fe Springs, Calif., said it is recalling the product labeled as monkfish because it may contain tetrodotoxin, a potent toxin.
While the frozen fish imported from China was labeled monkfish, the company said it is concerned that it may be pufferfish because this toxin is usually associated with certain types of pufferfish.
Eating foods containing tetrodotoxin can result in life-threatening illness or death and the toxin cannot be destroyed by cooking or freezing.
The company said two people in the Chicago area became ill after eating soup containing the fish.
