Health warnings remain for Auckland beaches about toxic sea slugs although it has been three months since the outbreak that killed six dogs.
"Slugs are still out there and still have the toxin in them," said medical officer of health Simon Baker.
"So we can't downscale our advice until eitherthey go away or they are without the toxin."
The Auckland Regional Public Health Service website advises people to keep in mind the potential ongoing risk to children and pets and not to let them handle or eat anything found washed up.
In August and September, 15 dogs became unwell with symptoms of poisoning from the toxin known as TTX after eating sea slugs at beaches in the Hauraki Gulf.
Six dogs died.
The toxin had been found in tropical puffer fish but not previously described in sea slugs.
Dr Baker said scientists from the Cawthron Institute in Nelson checked for sea slugs last month and found about 20 in half an hour.
They contained the toxin.
"But they were in waist-deep water - not washed up on the beach where a child or dog might pick them up.
"You won't die from absorbing them moving across your skin through seawater because any toxin will be washed off."
Dr Baker said it was thought the slug was an annual species which bred, washed up on the beach and died. This was possibly what happened last August and September.
Paul McNabb, the institute's technical manager, said the slugs came into shallow water to breed and became stranded on the beach.
"Now they are in plenty of water so they are not washing up where the dogs can get them."
After the outbreak, the Auckland Regional Council and other agencies which were responding to the dog deaths asked the Government to pay for more research.
They told the Ministry for the Environment the problem was of national significance and asked the ministry to take over.
A report to the council by the institute was attached, saying toxic slugs could be in beaches in other parts of the country but scientists could only find that out with more research.
Ministry spokesman Steve Long said yesterday that while the ministry would keep watch to determine whether there was a risk at a national level, the matter was one for local authorities to deal with.
