The suit claims Trader Joe’s underfilled 5-ounce cans of its store-brand tuna and violated the federally mandated minimum standard fill of 3.23 ounces for these cans. The purported class action was filed Tuesday against the company and a subsidiary in Manhattan federal court.

Tests by the U.S. National Oceanic and Atmospheric Administration showed the cans contained an average of only about 2.43 ounces to 2.87 ounces of tuna, depending on the tuna version, according to the suit.

Because the tuna cans are substantially underweight, the suit alleges the cans are “illegal for sale in the United States.”

In a statement, Trader Joe’s spokeswoman…