Tokyo is set to relax its strict controls on the sale of the poisonous puffer fish, a dangerous but highly-prized delicacy known for making the occasional diner very sick, a city official said.

Under present rules no “fugu” can be served in restaurants in the Tokyo Metropolitan area by anyone other than a specially-trained and licensed chef who has removed the most poisonous parts.

But an amendment being debated by the local legislature would allow eateries to sell fish that have been prepared off-site.

Tokyo consumers have long bought fugu meat from other areas of the country via the internet, most notably from the southern Kyushu region known for the food.

Supermarkets in Tokyo also sell fugu meat from other regions that were processed by trained chefs, the official said.

“We believe the amendment is a way to address” the gap between the reality and the regulations, the official said.

Fugu is a seasonal and much sought-after delicacy that often commands high prices among diners, who report the mild toxicity of the meat can cause a tingling of the lips.

Stringent regulations and the industry’s efforts have made deaths by eating fugu meat extremely rare, but a hand-ful of fishermen who eat their own catch are reported dead every year. Some aficionados ask to be served the banned parts – the liver and the skin – which are said to be a fine but dangerous delicacy.

In December, the Tokyo government revoked the licence for a chef at a Michelin two-star restaurant in the upscale Ginza district who served the fish’s liver to a diner who asked for it.