Patients with allergies have been at "ongoing and significant risk" from the meal service at Auckland hospitals, the DHB has found.

One patient suffered an allergic reaction after the wrong meal was delivered and there have been 25 near-misses at Starship hospital in the past year.

The meals are made by Compass Group, which supplies other DHBs across the country as well as about 300 sites including rest homes, schools and university dorms.

Its contracts with DHBs have caused controversy in the past, with protests outside Dunedin Hospital over what some patients called "disgusting slop".

The multinational now faces a serious issue over its contract with Auckland DHB, which has carried out a full review of inpatient food services.

The DHB's latest hospital advisory committee was informed by officials of the "ongoing and significant risk". According to the minutes from a meeting of the committee changes had been made, however, some issues were yet to be resolved with Compass.

An Auckland DHB spokeswoman said there were times when patients with allergies or dietary requirements got the wrong meal.

She was unable to confirm how many incidents there had been, but said at Starship there had been 25 in the past year. That was "extremely low" given how many meals were served.

"In all 25 cases the mistake was picked up before the child ate anything ... so far as I am aware there has been one incident in the past three years where a patient developed an allergic reaction after consuming an inpatient meal. No permanent harm resulted."

As a result of that mistake and "intermittent but ongoing issues" a full review was carried out, and the recommendations are being implemented.

There was always the chance of an error and there were protocols to guard against this, including having nursing staff double-check special meals.

In a statement, Compass said it worked closely with Auckland DHB to make sure all meals were safe and nutritious, and any issues quickly addressed.

Allergy oversights can be life-threatening. Melbourne's Frankston Hospital changed procedures for tracking allergy-free meals after the 2015 death of patient Louis Tate.

The 13-year-old with severe allergies died from a reaction to anaesthetic given to him after he suffered an anaphylactic attack while eating breakfast.

Mark Dixon, chief executive of Allergy New Zealand, said the not-for-profit society was aware there had been incidents at Auckland and other DHBs.

Given how serious reactions could be, it was very common for food allergy patients to take their own food in to hospital, he said.

Canterbury District Health Board last year declined to renew its contract with Compass and now prepares meals using its own kitchens, citing cost savings and more control over food on offer.

Compass Group NZ is wholly-owned by British multinational Compass Group PLC, the largest contract foodservice company in the world.

The deal to sign contracts with Compass was made to DHBs through NZ Health Partnerships, an agency set up to act on behalf of health boards and find savings through economies of scale.

Auckland, Counties Manukau, Waitemata, Southern, Nelson-Marlborough and Tairawhiti signed up, but have faced increased charges because other DHBs declined to come onboard.

The Compass contracts became a political issue after a large number of complaints when the new meals started being served at Southern DHB hospitals from January 2016.

Jonathan Coleman, Health Minister at the time, was challenged by Labour's former health spokeswoman Annette King to eat the "slop", and sampled pea and ham soup and other delicacies. His verdict: "Standard Kiwi fare."