Auckland Regional Public Health Service has had reports of people being sick after visiting beaches on the region's east coast, but says there's no clear link to the toxin scare.
Devonport resident Deana Busch says her two-year-old daughter became ill after visiting Narrow Neck Beach on the North Shore, where at least one dog has died from tetrodotoxin poisoning.
Mrs Busch says her daughter Natasha began vomiting five minutes after she accidentally sipped sea water as she played on the beach a few days before the first public health warnings were issued.
In a statement, the Auckland Regional Public Health Service says it is aware of a low number of cases of human illness following visits to a Hauraki Gulf beach, but there is no evidence to link these cases with tetrododoxin.
"There are currently no new reports or ongoing investigations into cases of human illness following visits to Hauraki Gulf beaches," it says.
North Shore City Council says it not been notified of any other children falling ill.
Auckland Regional Council expects test results on a fifth dog that died after visiting one of region's beaches this week.
Scientists have discovered tetrodotoxin in dead sea slugs, which is believed to have caused the deaths of several dogs on eastern beaches. The poison is normally found in puffer fish.