The government has ruled out a law change to allow victims of the Havelock North water contamination to make a claim to the Accident Compensation Corporation.
More than 5000 people fell ill last winter when campylobacter contaminated the town's drinking water supply. At least three contracted a serious nervous system disorder.
ACC said it received one or two claims over the outbreak and declined them.
It said inhaling or ingesting a virus or bacteria was not considered an accident, unless it was the result of a criminal act.
Lawyer Phil Schmidt said there was a glaring hole in ACC law, preventing help for those with ongoing health problems.
The office of Immigration Minister Michael Woodhouse said he was not considering a law change.