Doctors believe three people left gravely ill after eating wild boar are suffering from botulism, a Waikato Hospital spokeswoman said this afternoon.

"While we don't know the exact cause and source of this illness, we now believe it is botulism. The three patients are responding to botulism anti-toxin and are recovering in hospital.

"We have sent samples off to a specialist centre in Queensland for testing but it may take several weeks before we get the results. We have no evidence to believe there is any public health issue."

Husband and wife Shibu Kochummen, 35, and Subi Babu, 32, and Kochummen's 62-year-old mother, Alekutty Daniel fell ill a week ago after eating what is thought to have been contaminated wild boar. All are stable in the Hamilton hospital's acute ward.

Botulism, a rare and potentially fatal illness, is caused by the bacteria Clostridium botulinum. Symptoms can include vomiting, muscle weakness and paralysis.

Family friend Joji Varghese said earlier this afternoon doctors were keen for people to know the trio were ill because of the rare toxin.

"I asked 'should I use this word?' They said 'yes, it's about time somebody should start saying that word'."

Treatment is already under way, and all three had shown signs of improvement, Babu being moved this afternoon from the high-dependency unit to join her husband and mother-in-law in the acute ward, Varghese said.

All are expected to survive, but face a long road to recovery - perhaps as long as four to six months, and they may be left with disabilities.

The speed and nature of recovery was individual, so the exact prognosis for the trio was not known, he said.

None could yet talk or swallow and while they had opened their eyes, it would be inaccurate to say they were conscious.

Babu and Kochummen have two daughters, aged 7 and 1, who are in the care of church members until an aunt and uncle arrive from India in a few days.

The oldest daughter had been taken to see her parents once, but that was not likely to be repeated in the near future, Varghese said.

It was dawning on her that her parents were not going to get better quickly, he said.

"The kids are coping [but] they are sad, especially the elder one ... there's that look of abandonment, 'why are my parents not talking to me?' And 'I'm not where I belong'.

"The sooner we hand them over to familiar faces, the better. I'm hoping that will put them more at ease."

- NZ Herald