The meat of toxic puffer fish has been passed off as salmon by fish suppliers in Thailand, killing 15 and hospitalising a further 115 over the past three years.
Dr Narin Hiransuthikul of the Chulalonkorn University Hospital in Bangkok said that, although banned in 2002, puffer fish continues to be sold in large quantities in Thailand's markets and restaurants.
"Some sellers dye the meat of puffer fish and make it look like salmon which is very dangerous," Narin told The International Herald Tribune.
Narin said that 115 people have been hospitalised after eating illegal puffer fish in Thailand and 15 people have died.
FuguPuffer fish meat, which is known as fugu in Japan, is considered a delicacy and in Japan can only be prepared by highly trained fugu chefs.
The meat contains a toxin called tetrodotoxin, or TTX, which is produced by bacteria living within the fish and can prove deadly if small quantities are consumed.
Trained fugu chefs leave trace quantities of the poison in the fish meat, which causes a tingling sensation on the tongue when the fish is eaten.
However, too much of the toxin can result in paralysis, asphyxiation and heart failure.
TetrodotoxinTetrodotoxin is formally known as anhydrotetrodotoxin 4-epitetrodotoxin and is produced within the fish by specific strains of bacteria.
It is found in many members of the Order Tetraodontiformes, which includes pufferfishes, porcupinefishes, trigger fish and sun fish.
Small quantities of TTX can induce respiratory problems that can lead to death, particularly if the toxic flesh has been eaten.
There is currently no antidote to the toxin and death can occur within 20 minutes and eight hours of ingestion.
DrugsThe puffer fish has become a target for scientists working in the field of drug discovery.
In 2003, scientists succeeded in isolating an active ingredient of the poison without the deadly side effects.
The result was a non-addictive pain-killing drug called Tectin, which is claimed to be some 3000 times stronger than morphine, with effects lasting between eight and 21 days, with no side effects. (See Puffer could help ease pain)