Sunflower seeds are frequently contaminated with a potent toxin produced by moulds posing an increased risk of liver cancer, a US-based study warns. Aflatoxin, produced by Aspergillus moulds commonly infects corn, nuts, and sunflower seeds, researchers said. Chronic exposure to the toxin causes about 25,000-1,55,000 deaths globally a year from corn and peanuts alone, they added.