Research, Science and Technology Minister Wayne Mapp is backing calls for Government ministries to help pay for a study of toxic sea slugs.

Scientists want to know how far the highly poisonous slugs have spread and why they have suddenly become toxic but the Environment Ministry and other government departments have so far refused to pay.

Pleurobranchia maculata, or grey side-gilled sea slugs, and the poison they carried, tetrodotoxin (TTX), were linked to the deaths of 13 dogs at Auckland and Coromandel beaches last year and the Auckland Regional Council and other agencies involved in a joint response want the Government to pay for research to find out if the problem is nationwide.

But the Ministry for the Environment says it is a local problem, and any long-term monitoring should be developed by councils with the Ministry of Health and New Zealand Food Safety Authority.

A spokeswoman for the Ministry of Health has said toxins in the marine environment were a problem for the Environment Ministry and it should be approached for funding.

Meanwhile, the ARC said because of the cost involved, it and others on the response team would continue to seek money from the Government.

Dr Mapp said he would write to Environment Minister Nick Smith and Conservation Minister Kate Wilkinson and ask them to help secure funding for the research.

He said the risk of poisoning from sea slugs was low but the risk of harm if you were poisoned by one was high.

"The amount that was fatal [to a person] was as low as half a slug - one teaspoon," he said.

He believed more work was needed to find out how the slugs came to be toxic. TTX was usually found only in sea creatures living in the tropics, he said.

No one has been reported poisoned by sea slugs but health authorities have warned people to take care on beaches.

The breed of slugs that killed dogs in Auckland and Coromandel lives in the waters off both islands of New Zealand.

Every slug tested so far has been positive for TTX, all but one from Auckland.

The joint agency response includes representatives from local councils, MAF Biosecurity, the Department of Conservation and the Auckland Regional Public Health Service.