Three adults are lying in a vegetative state in a North Island hospital and may be paralysed for life after eating what is thought to be contaminated wild boar.

The family trio from Putaruru are being treated in critical care units at Waikato Hospital after a severe case of suspected food poisoning.

Shibu Kochummen, his wife Subi Babu and his mother Alekutty Daniel were found by paramedics lying unconscious in their home on Friday night after Kochummen collapsed midway through making an emergency call for help.

The gravely ill husband and wife and mother-in-law are now largely unresponsive and in a vegetative state with only brief spells of consciousness.

A priest visited the hospital on Sunday to pray for the afflicted family and friends from the Hamilton Marthoma congregation have been making daily bedside visits.

Close friend Joji Varghese said today it was widely suspected they had been poisoned after eating a dish containing contaminated wild boar that Kochummen had shot on a hunting trip.

Varghese said the game meat, which has been taken away for testing, was the only item of food the couple's young children did not eat during their evening meal.

"The neighbours told me within 30 minutes of eating their meal they were throwing up at 15 minute intervals. Shibu rang 111 and fainted through the conversation.

"When the ambulance arrived at the home they found three unconscious people in the house."

He found out a day later his good mate, wife and mother were hooked up to life support machines in hospital after he failed to turn up to his child's baptism on Saturday.

Since then neighbours and members of their Hamilton Anglican church congregation have rallied around the stricken family taking care of the couple's young children and liaising with health, embassy and welfare authorities.

Doctors are understood to be puzzled at the dire impact of the suspected poisoning.

Findings from a detailed toxicology report are expected tomorrow.

Varghese said it was incredibly difficult seeing his dear friend, who had embraced New Zealand life to the full since shifting here five years ago from India, in such a wretched state.

"These were extremely active, full of life people and all of the sudden, nothing," he said, breaking down in tears.

"When I visit him I imagine what's going through his head and I'm telling him to not worry about it, 'We've got the children and we're talking with your family and they'll be here shortly'."

He said medical specialists had indicated it could take up to two months for the poison to clear their bodies.

But there was a possibility if they ever regained consciousness they might suffer long term damage including paralysis or tremors.

The couple's two children - a 7-year-old and 1-year-old - are being looked after by the church group.

But the matter is complicated with the couple's mother, who is on a visitor's visa and does not have medical insurance.

She will need to foot full medical costs for treatment that could take up to six months or more.

The Indian High Commission and Ministry for Vulnerable Children have been approached to help the family.

Relatives in India say they are willing to come to New Zealand to care for their loved ones once they are discharged from hospital.

A plea has gone out to members of the Indian community across Waikato and Auckland for funds to pay for household bills and expenses associated with their health care.

"Please consider this message as a plea to the wider Keralite/ Indian / Kiwi community to support the family in this hour of crisis and uncertainty. The needs of the family are many and funds are few," said an email.

Indian High Commissioner Sanjeev Kohli said embassy staff were working with family and friends to do whatever they could to help.

"We remain deeply concerned," said Kohli. "It's a really unfortunate incident."

He said embassy officials were liaising with family in India as everyone worked out the best way to care for couple's children.

The Waikato District Health Board and the region's medical officer of health have been approached for comment.