A grieving daughter has issued a dire warning for seafood lovers after an expensive Japanese fish delicacy fatally poisoned her parents.

Malaysian couple Ng Chuan Sing and Lim Siew Guan both died within hours of consuming fried puffer fish which they purchased, assuming it was another species, from an online trader earlier that day.

The pair, both in their early 80s, weren’t aware the fish was poisonous and quickly experienced breathing difficulties and shivers, Malaysian authorities claim.

They were rushed to hospital later that day, before being admitted to the intensive care unit where Lim died at 7pm that evening.

Following his wife’s death, Ng was put into a coma for eight days but his condition deteriorated and he died on Saturday.

Now, their child Ng Ai Lee is pleading with authorities to strengthen laws for fishmongers in a bid to prevent the same situation happening to another family.

Lim Siew Guan lost her life just hours after consuming the fish. Photo / Supplied

“Those responsible for their deaths should be held accountable under the law and I hope the authorities will speed up investigations,” Ng told reporters at a press conference on Sunday.

“I also hope the Malaysian government will beef-up enforcement and help to raise public awareness on puffer fish poisoning to prevent such incidents from happening again.”

Her pleas, which were made ahead of her parents’ funeral, come as at least 30 puffer fish species infiltrate Malaysian waters.

Ng said she has informed the fishmonger of her parents’ deaths and is yet to receive an apology.

“We welcome the fishmonger to come and pay his last respect,” she said.

Ng Chuan Sing was in a coma for eight days before he passed away from the poisoning. Photo / Supplied

Puffer fish, of “fugu” in Japan, remain an enjoyed delicacy among upscale restaurants in Tokyo despite its high-toxicity risk.

Almost all puffer fish contain tetrodotoxin – a substance that is 1200 times more toxic than cyanide for humans, according to National Geographic.

Also known as blowfish, the toxic substance makes the species foul tasting to animals which also protects them from predators.

Qualified chefs who cook puffer fish are said to undergo at least three years of intensive training to learn how to remove the high concentration of toxins in its body.

These toxins are usually located in the fish’s internal organs, skin, blood and bones.

If ingested, symptoms of poisoning typically develop within 10 to 45 minutes of consumption and include numbness, tingling around the mouth, salivation, nausea and vomiting.

Puffer fish contain a poison that attacks the nerves and causes death to the victim. Back in 2017, a washed-up puffer fish was seen on Mount main beach. Photo / George Novak

WebMD also said symptoms may progress into paralysis, loss of consciousness and respiratory failure.

“Vomiting should be induced if the poisoned person is awake and alert and has eaten the fish within three hours,” the medical website advised.

“The person may become paralysed. Artificial respirations may keep the person alive until medical attention in a hospital’s emergency department is possible.”

According to Malaysia’s Ministry of Health (MoH), between 1985 and March this year, there have been 58 cases of puffer fish poisoning and 18 deaths reported in the country.

The couple's daughter Ng Ai Lee is now advocating for tougher fishmonger laws. Photo / Supplied

While laws state puffer fish can’t be sold under Section 13 of the Food Act 1983, they’re still illegally available at some wet markets as highlighted in Ng’s parents’ case.

Now, as investigations into their deaths continue, the MoH is desperately working to educate the public about food safety and the dangers of consuming puffer fish that’s not been cooked by professional chefs.

“Puffer fish contain a poison known as tetrodotoxin that attacks the nerves and causes death to the victim. Almost all types of puffer fish contain toxins and can lead to poisoning if eaten in the wrong way,” the MoH posted to Twitter.

“Accordingly, the public is advised to seek immediate treatment if there are symptoms of poisoning such as muscle weakness, nausea and vomiting within 30 minutes to 2 hours after eating puffer fish.

“Do not eat if you’re not sure it’s safe.”

- Rebecca Borg, news.com.au