Unscrupulous vendors in Thailand have been selling meat of the deadly puffer fish disguised as salmon, causing the deaths of more than 15 people over the past three years, a doctor said Thursday. Although banned since 2002, puffer fish continues to be sold in large quantities at local markets and restaurants, said Narin Hiransuthikul of Bangkok's Chulalonkorn University Hospital. "Some sellers dye the meat of puffer fish and make it look like salmon which is very dangerous," Narin said. The ovaries, liver and intestines of the puffer fish contain tetrodotoxin, a poison so potent that the US Food and Drug Administration says it can "produce rapid and violent death." The fish is called fugu in Japan, where it is consumed by thrill-seeking Japanese gourmets for whom the risk of poisoning adds piquancy.