A Waikato family thrashed wildly, behaved like children and laughed at nothing during stages of their recovery from a mystery illness.

Botulism, the initial diagnosis, may not have caused the poisoning of three Waikato family members.

And the wild boar meat is also being ruled out.

Supplied Shibu Kochummen, 35, his wife Subi Babu, 33, and his mother Alekutty Daniel, 62, were found unresponsive on the floor of their Putaruru home on November 10. They spent a month in hospital.

The Waikato District Health Board confirmed botulism and 1080 tests both came back negative.

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Shibu Kochummen, 35, his wife Subi Babu, 33, and his mother Alekutty Daniel, 62, were found in a vegetative state on the floor of their Putaruru home on November 10 after eating a wild boar curry.

Supplied Subi Babu, 33, was the last to be discharged from hospital.

But the cause remains a mystery.

In a statement the Waikato DHB said investigations into the source of the family's illness was ongoing.

"However there has been no evidence of any public health threat. There is also no evidence that the family's illness was caused by the pork they consumed. It is great news that the family continue to recover," Medical Officer of Health Dr Richard Vipond​ said.

LUKE KIRKEBY/ STUFF The Kochummen family's Putaruru home where they were poisoned.

Botulism tests in the food were also negative.

Mercury, arsenic and lead have all been tested for, family spokesman Joji Varghese told the TV Wild Show YouTube channel, but so far, there have been no positive results.

Friends close to the family - who are now out of hospital and recovering at home - know they might never find out exactly what caused the illness.

The family responded to the antitoxin for botulism, but faster than expected, Varghese said.

"If it is a typical case of botulism, we were told the antitoxin would take longer to work. But in this case, the progressive paralysis stopped within half an hour or so of the antitoxin being administered, which was the big question mark," Varghese told the TV Wild Show.

But the meat remains the focus of the family's sickness.

Kochummen found a bowl of the wild boar curry still in pristine condition when he and his mother returned home 35 days later.

Everything else had gone rotten.

"It still looks pristine. If you didn't know what it was, you would pretty much eat it," Varghese told the TV Wild Show.

In hospital, the trio had suffered violent thrashing as well as paralysis and vomiting after eating the pressure-cooked and pan-fried boar.

They had to be tied down, restrained by three to four nurses, while their bodies thrashed around, Varghese said.

Sometimes their eyes would be open and bulging while they were unconscious.

"[Daniel's] legs would actually flip 180 degrees, just flip backwards on the bed," Varghese told the show.

"There was a huge possibility of her hurting herself."

"There was a phase when they would behave quite like children, smile at nothing, laugh at nothing - just giggle away."

He said the three are recovering well.

Kochummen himself was not a hunter, but he had a chest freezer full of game meat, full of home kill from various friends. ​

Waikato Hospital have been in touch with Centers for Disease Control and Prevention (CDC) in the United States.

"They [CDC] wouldn't say it was botulism, either," Varghese said.

The family had been told they would find out further results by the beginning of March at the earliest.

The three plan to celebrate Christmas with their church.

But they'll stick to meat-free dishes, Varghese said.

"​They're eating OK, but they are staying away from meat for understandable reasons.

"By the looks of it, all of them have gone vegetarian."

The mental strain of the incident had been particularly hard on Babu, Varghese said.

"She kind of relives the incident over and over again, especially in her sleep.

"She had continuous panic attacks before being released by the hospital."

But those have stopped and she's much better, Varghese said.

Their short term memory capacity is almost completely recovered.

"The biggest hurdle at the moment is their constant fatigue. They walk five minutes and are basically out of breath. And also, every joint, every bone, aches all the time."